Are you finding it Snappier(tm) ?
I just installed it in the past hour thought it takes a bit more time to load thumbs and previews, but the way it responds to sharpening and denoising is (or at least seems to be) much quicker, though it still really loads the processor up ... it'll take me a few more days of use to see if it feels generally more agile than 4.0 and 4.1, but I'm feeling vaguely optimistic