The A7 is a big improvement from the NEX-6; it feels more substantial and the larger body of the A7 is actually welcomed, since it helps with a better grip on my hand. The addition of the front scroll wheel is definitely a plus. With AF lenses, it can be used to select the aperture, and when set to Shutter Speed priority, it can be used to control the shutter speed, with both AF and manual focus lenses. As I said before, the exposure compensation dial doesn't really need to be there; it's kind of redundant. Physically, I like the A7 much better than the NEX-6, but there are somethings that I like better on the NEX.
The magnifier button (C2) is at the same location as is on the Olympus E-M5's Playback button, which I really hate. I can not magnify the picture without using both hands, because the button is too far from my thumb without loosen my grip on the camera. On the NEX-6, I can program the ENTER button to enlarge the picture, which I can operate with one hand and it works perfectly.
The Live-view magnify feature now takes two button pushes to activate, instead of one on the NEX-6. This is similar to how the the Olympus E-M5 works. It makes no sense to me. If I want to magnify the area I am focusing on, I want it magnified when I push the button, not to select the area I want to focus first, because I almost always use the centre position. Besides, I can still move the magnified area if I need to. It is possible that I haven't setup the camera correctly.
These two issues are my biggest complaint so far. I can live with them, but it sometimes drives me crazy.
Lawn Chair - Sony A7 & Canon nFD 50mm f1.2 @ f1.2. Click for larger.