On the NEX noise comparison:
I completely agree with the point about the emphasis on high ISOs. If you run into a guy who can't possibly use a camera because it doesn't have a clean ISO 6400, you've just met a guy who shouldn't be a photographer. Fifteen years ago, I would have killed for a good clean 800...in film. To me, a clean 3200, with adjustable white balance yet, is like a miracle. I've been shooting a Panny GH2 with the Nocton f0.95 and the lens is soft, but jeez, I don't care -- I can shoot in the dark.
At the margins, the 5 is cleaner than the 7, but I doubt most would see much of that in a print. But one thing that has bothered me about good, clean, say ISO 1600 photos with high-resolution cameras, is that you can see *everything.* Like dandruff. The 5's smaller size looks cleaner partly, I think, simply because you don't see so much crap sticking to the targets. It's really there, but who needs to see it?
Is it possible that the real sweet spot for all 35mm-category cameras (that is, everything from the Nikkon V1s to FF), might be about 18mp?
I have to say that the commentary I've seen lately suggesting that 16-18mp is better than 24mp because of space and processing requirements, is silly. Storage and processing speed and ram are cheap.