OK, after a few days of shooting quite a bit with the GR, spending a full day trying to work out getting the color profile to work with Lightroom, and more than a month with the Coolpix A, I'm ready to offer final thoughts on these two cameras:
There's ultimately amazingly little difference between them. I think we pretty much understood that going in, but I can confirm it for sure now.
The image quality, once the color processing issues are taken care of with the Ricoh, is just indistinguishable:
* For beautiful sunny day outdoor shots, importing the Nikon files and the Ricoh files into Lightroom using the Adobe Standard color profiles for both results in images that are remarkably similar, with the only difference seeming to be a slightly warmer WB assumption from the Ricoh. I actually prefer what the Nikon brings in, but a slight tweak to white balance and they're identical - in either direction, so no reason to base any sort of decision on this.
* The Ricoh seems to have developed a reputation for sharper corners on the lens. Wide open at f2.8, doing the ubiquitous brick wall test, I can only say that if there's a difference its barely noticeable at 100% at f2.8 and is gone by f4, and would never matter at any sort of normal viewing size. This second Nikon copy I have seems to have a slightly de-centered lens because the upper left corner is a bit soft at any aperture, but the others are quite good, right in line with the Ricoh. Both are astoundingly good. Compared to the Fuji 18mm lens on the X-Pro or X-E1, both of these lenses are vastly sharper in the corners at wider apertures.
* Low light, similarly seems about identical. The DXO tests seem to give a slight edge to the Nikon here - only about a third of a stop, and the Camera Store guys gave the Ricoh the edge, but I can't see anything, not that I'd likely notice a third of a stop anyway. Both are good up to 6400, basically useable at 8000, and generally not too good from 10000 and up. Both have very workable noise/grain patterns and I've got plenty of shots from both at those higher reaches that I'm pleased with.
* Metering - I agree with Ming Thein that the Nikon's metering is more dead-on more often. It just never misses. But I don't think the Ricoh meter is at all bad. I'm inclined with most digital cameras to use -0.3 of exposure compensation as a starting point. With the Nikon I tend to just leave it on 0 as a default. The Ricoh works just fine at -.03. Both are just fine, the Nikon's a bit better.
Focus:
* Auto focus varies somewhat. In bright light, the Ricoh is faster. I don't find either slow and neither is OMD fast, but the Ricoh is the faster of the two. In medium light, typical indoor light with plenty of light coming in the windows or good internal illumination, they seem very similar - about as fast as the Nikon is in good light, but the Ricoh comes down slightly to that level. In low low light is where the biggest differences are, but I couldn't name a winner. Both kind of suck in their own special ways. The Ricoh just slows WAAAAY down, but it'll lock eventually. It'll go on some extended hunting expeditions but eventually seems to lock. The low light speed and behavior seems very similar to the GXR, at least with the 28mm lens module, for those familiar with that The Nikon is much much faster, but often its just faster to tell you it can't focus. In less than a second or so you'll either get focus confirmation or a the red square indicating it didn't find focus and its given up the search. Neither are in the class of the Fuji cameras or the RX1, which aren't fast, but are very very reliable.
* Manual/Zone focus is just a matter of preference, both work wonderfully. Ricoh has its beloved snap focus, which is quick and easy and wonderful as a way to zone focus. Nikon uses a focus ring on the lens with a distance scale. Ricoh can also do pure manual focus, but to adjust it you have to hold down the macro button and turn the front control dial. This is the same adjustment for changing snap focus distance (a welcome return of this option after leaving it off of the GRD4) but it just isn't a terribly pleasant way to adjust manual focus to me. The GREAT part about the Ricoh is that its easy to assign a function key to toggle between snap focus and auto-focus and the snap distance, by definition, is sticky. So you can be zone focussing at 1.5 or 2 meters, switch instantly to auto-focus, focus on something close to infinity, switch instantly back to snap focus and you're right back at 2 meters. There's also a very nice electronic DOF scale on the Ricoh - I usually hate these but the versions on the Ricoh APS sensor cameras seem to be very consistent with DOF Master assumptions and that's a good place to work from for me. The manual focus, unlike snap focus, does NOT seem to be sticky, which is odd because it was on the GXR. I've heard conflicting reports on this, but I can't seem to find a way to make manual focus stick, so I'm assuming its not. The Ricoh also has four different versions of focus peaking, which I would never have any use for on a 28mm fixed lens camera, but if you like it, you've got it. The Nikon doesn't automate manual focus at all, but surprisingly (to me), I find it nearly as quick to work with as the Ricoh. The manual focus distance is not sticky - after a power down it always resets to infinity, and after a round of AF shooting its just left at the last AF distance. But the focus ring has a short enough throw that I seem to be able to get from anywhere to about 2 meters (5-6 feet, or around 2 meters is my starting point for zone focus in most circumstances) in about a second, two seconds tops. AF/MF is switched with an external switch on the side of the camera and it it takes me half a second to switch from AF to zone/snap focus on the Ricoh, it only takes me a second or two on the Nikon. I guess if you switch back and forth fast and often, this might matter. To my surprise, I found I was just as happy with the Nikon, despite the seeming extra steps involved. Also the Nikon does not have a DOF scale, but if you've been doing zone focus for any length of time you shouldn't need one. I know my distances and apertures and how they work together and about what my in-focus zones are. And personally, when I need to changed distances on the fly, I just greatly prefer giving a manual focus ring a slight turn rather than pushing buttons and turning dials to change the snap focus distance - purely a personal preference but a strong one. Finally, Nikon has nothing like the "full press snap" feature of the Ricoh, so if you use and love that feature, you've gotta go with the Ricoh. I never liked or used it, but many swear by it.
I have to say as an aside here, that both of these cameras make me realize how absolutely WONDERFUL the GXR-28 is for focus (except that the AF is deadly slow in any light). But in terms of how it functions, its just the best of all possible worlds. It has snap focus with all of the same snap-focus tools as any other Ricoh. Its also got great manual focus with a focus ring on the lens that works really well with the distance/DOF scale on the screen. Either can be toggled directly from AF and both and snap AND MF distances are sticky. Its EXACTLY how I'd ask someone to design such a system if I was in a position to ask. The only thing I like better is the "snap-ring" lenses that Olympus has developed (the 12 and new 18mm lenses) and the new Fuji 14mm has joined. These are great, awesome, and wonderful because the focus distance is marked on the lens, the snap between AF and MF is instant, and the MF distance is always sticky. If Olympus made a small Pen with a silent, or even reasonably quiet shutter, that would be my favorite street setup. Its ONE of my favorites as it is, but with a quieter shutter, there'd be nothing better even CONCEIVABLE to me...
Controls: I've written about this a lot already. Suffice it to say that the Ricoh has about 100,000 ways to customize almost anything you want to do with the camera. I have yet to think of something I might like to be able to do quickly and not be able to set the camera up to do it quickly. For many people that's a BIG plus. For me, it really doesn't end up being a plus because when I try to take advantage of more than a few of these options, I find myself getting confused about what I put where, particularly if I have two or three custom setups (and you can have a lot more than 2 or 3 if you want 'em). The Nikon has a couple of customizable buttons and a couple of slots for custom setups and that's about it for customization. For me, that's plenty, for some, that's horribly lacking. The Nikon was also designed to be a two handed camera, with some key controls on the left side and others on the right and there are combinations that require two hands. I've set it up so that I can shoot about 90% of the time with one hand, though, so that is possible if it matters to you. The Ricoh is designed as a one handed camera from the start, so if that's important to you one way or the other, those are the options. One last note - I sometimes find I'm lost in some Rube Goldbergian invention when I'm setting up a Ricoh. I've done it enough times that I can get around it pretty easily, but there are just SOOOOO many options for how to accomplish any task, its almost funny. There is something about the relative simplicity of the Nikon interface that I find oddly reassuring. Some things you just can't do immediately and you have to go to the menus, or at least the I button. But almost everything you have to get to in a hurry the VAST majority of the time is immediately at hand and there's no clutter of additional controls. Once I've set up the Ricoh to my liking, it can operate about as simply as the Nikon with quicker access to additional features, but the starting point can be pretty imposing. And if you start getting too far into all of the possible settings on the Ricoh, you can get really lost and it can hurt your head. And this is from someone who's been using a Ricoh interface a LOT for a couple of years now.
Miscellaneous
* Camera feel - this is obviously a HUGELY subjective area, but the Ricoh just feels amazing in the hand, like it was designed to rest there comfortably. Its slimmer so a somewhat more comfortable shirt pocket carry, but its when you pull it OUT of the pocket and handle it that it really comes into its own. The Nikon feels great - when I'm using it I don't miss the Ricoh, there's absolutely nothing wrong with the Nikon in this respect. But when you use them back to back, the Ricoh just clearly wins for me in this respect. I remember the first time I ever handled a GRD3 and how perfect it felt and this GR is essentially the same body, with a MUCH MUCH bigger engine inside.
* Startup time - from a bit of highly informal testing, I think the Nikon has a slight edge here. Only a fraction of a second, but it seems to be a repeatable result, so I'm sticking to my guns on this. But its not enough time difference to matter. What DOES matter though is the WAY you turn the cameras on. Ricoh has a little tiny button, recessed at that, that you need to push down to start the camera. Its not terribly difficult but its relatively fiddly enough that I've occasionally gone to start the camera and then realized I missed, or didn't push it far enough or something. The Nikon, OTOH, had a rotary switch around the shutter button. It spring loaded so its not like the Fujis or the RX1, but you pull it back to turn the camera on (and it springs back to its initial position) and then you pull it back again to turn the camera off. The ease of using this thing and the way its RIGHT at the shutter button, makes reaching for this camera, turning it on, and being ready to shoot, a rather sublime little experience. There's a lot to like about the Nikon but this little tiny detail is one of my favorite things. The Ricoh isn't a problem in this regard - I'd never give this difference more than a tiny amount of consideration in a purchase decision, but if you buy the Nikon, this is something you'd come to love, I promise.
* ND filter - the Ricoh has an ND filter and the Nikon doesn't. Not a huge deal but a very nice thing if you like to shoot wide open in bright light. The coolest thing about the Ricoh ND filter is that it can be set to come on automatically. So if conditions are too bright for the aperture and ISO and shutter speed you're using, or the max shutter speed and minimum ISO if those are being set automatically, the ND filter just comes on. Unless you see the notification on the screen, you'd never even realize it. Great, GREAT feature. A plus for the Ricoh for sure.
* Rear screen - the Nikon is real good in terms of visibility in bright light. The Ricoh is better, about as good as the Sonys because I think they use the same screen that Sony developed. Both are better than any camera in the world a couple of years ago and neither would be a problem, but the Ricoh is that much brighter and easier to read in super bright sunlight. On the converse side, the Nikon screen is remarkably smudge and fingerprint resistant - it seems to repel this stuff. The Ricoh, OTOH, seems magnetized to pick up all of the smudges and prints and dirt and dust that the Nikon repels. Any further evidence that these cameras are fraternal twins is un-necessary - they're like opposite ends of the same magnet, with one attracting every little fragment of dirt and grease imaginable, the other repelling it. A win for Nikon here.
* EDIT - one more thing, SHUTTER SOUND - Believe it or not, there's a real difference in the shutter sound. The Nikon is approximately silent. Obviously its not LITERALLY silent, but with the camera a foot or two from your ear in a very quiet room, you have to strain to hear the tiny little "snick" it makes. There is one, but I've never tried a camera that was quieter than this. The Ricoh, to my surprise, has a much louder click. Its not LOUD in any sense, but its clearly audible even from a few feet away in a quiet environment. Nothing that would ever matter on the street or in a crowded room, but its not what I'd call "museum quiet". This means absolutely nothing to me, but some folks want the quietest possible camera and the Ricoh isn't quite there.
OK, that's all I have for now and probably almost everything I will have, although I reserve the right to add a few items if they crop up.
Bottom line, IQ is basically indistinguishable in EVERY way that I'd ever consider to matter, with a nod to the Nikon for metering, but nothing that can't be easily overcome with the Ricoh. So any purchase decision should be based on the ergonomic and UI features and how you like each. They're two different cameras in this regard, but not all that radically different. I'm not absolutely sure yet, but I'm having trouble finding any solid reason, intellectually or in my gut, to spend an extra $300 on the Nikon. It would be a tougher call if they were the same price. Both are wonderful little cameras and I've been waiting for one of them for ages. I almost wish only one had been released - it would have eliminated all of this thinking and comparing and I'd have been absolutely thrilled with either one. But now we have two and its among the BEST problems I can ever imagine having. So, hooray for everyone who loves small fixed lens 28mm cameras - our time has come. You can't go wrong with either of these cameras - only question is if one is slightly more right for you than the other...
-Ray