I know some of you on here are connoisseurs of camera bags so I thought I might ask for some advice. I currently use a Lowepro Exchange Messenger bag and I'm looking for a replacement. I want something similar in style - over shoulder/messenger - and similar in size - able to carry an NEX camera with lens attached with room for up to two more lenses (all primes so nothing really bulky), my RX100 form time to time and the usual collection of cards, batteries etc. My one big requirement is that the main compartment has to have the option of zip closure as well as the usual buckles/clips. Ideally, I would also like something that comes with a waterproof cover, though that is not crucial. Finally if there were space to slip a 7" tablet in there that would be a nice bonus. It doesn't need to be anything fancy, in fact the less obviously a fancy camera bag the better. Any thoughts, recommendations, suggestions? Thanks.