Hi, didn't know there was a camera gear thread here, first post.
I used to own a Canon 5d MK II with several primes, loved the IQ, hated the bulk, the weight, carrying such a huge thing around is no fun. It ended up collecting dust at home most of the time, after buying a Fuji X100, I used the Canon maybe once in 6 months. And there were the stares and looks too, with a big DSLR you always look like a paparazzi or a nerd. So I sold it. I'm using mirror less cams now, but would love a full frame camera with 2 or 3 fast primes again, as that is the only look a crop camera can't fully reproduce.
The A7/r look great, but like with Sony's NEX system, the cameras are nice but the lenses are a joke, too slow, too big, too expensive for what they are. 800 for a 35mm f2.8? The 55mm is huge for its relatively slow aperture, let's not even get started on the price. Small body is great, too bad the lens isn't any smaller than a DLSR lens.
The advantages of full frame only come into full effect if you use the same spec lenses. The 23mm f1.4 for Fuji X, e.g., gives you the field of view and DOF of a full frame 35mm f2, so in comparison to this 35mm f2.8, you gain two stops of light, meaning two full stops lower ISO and a full stop of DOF control, despite the crop sensor. Why go for the expensive full frame when it gives me less DOF control and less low light performance than the cheaper smaller sensor alternative?
I have used Zeiss ZE lenses for Canon DSLRs and they are great, they have a very special rendering, very saturated and contrasty. But at least the DSLR lenses are somewhat competitively priced compared to their Canon/Nikon counterparts, and they are actually made by Zeiss, these are Sony lenses with a Zeiss badge. 1100 for a 55mm f1.8 is ridiculous.
Since Olympus is working with Sony now I hope they join this system. They make some of the best and compact lenses in the industry, they could make some useful lenses for these camera bodies, because these are not cutting it at all.