Just a quick report, though I don't have any images to share yet. I bought the A7 with the 35 F/2.8 and for some reason, I wasn't impress, maybe because I was expecting a lot more coming from a 5D MArk III body.
Then I sold it, bought the A7R + 55 1.8, and oh my golly! The sharpness, detail is astounding. Wow. Cropping at 100% never looked so good. I took a street shot of this lady crossing the street and at 100% crop, the details is as good as my 6D uncropped.
I'm still iffy about the system though only because I shoot studio and I find it uncomfortable for such use. But I guess overtime, I'll get used to it.