I'm surprised that shutter vibration has become the principal issue. My main concern is M lens compatibility from the standpoint of color vignetting and corner smearing. When my A7r body arrives I'll try the new Adobe tool, but I don't expect it to fix smearing.
From what I can gather so far, the WATE is an exception to generally poor performance in corners with lenses of 28mm and shorter. And I wouldn't want to bulk up with a WATE anyway. Unfortunately, some of the nicest 35mm Ms are problematic: Cron V4 and to a lesser degree FLE. With a couple of exceptions, the A7r seems to be a body suited mainly to Ms of focal lengths above 35mm.
Ironically, the samples I've seen suggest the 35mm that works best from the standpoint of color vignetting and smearing would be the CV f1.2. This seems ironic: I'd want a sensor capable of higher ISOs in large part because I'd hate to schlep a lens that size. I'm also puzzled by all the test shots that are appearing from A7rs with Noctiluxes. With higher ISOs, their largest apertures and tiny slice of DOF would be less advantageous from any standpoint but bokeh.
My needs are limited – I just want a high-ISO sensor to stand in for my M9 in problematic available light. I'm planning to use the body initially with only 40 Summicron and 50 Sonnar-C. Both have looked good corner-wise in the test shots that have appeared (esp. on FredMiranda). I'll be looking for an A7r-compatible 35 that's smaller than my FLE, because I won't have much need of f1.4 at higher ISOs. When Sony/Zeiss come up with a 28 that matches the A7r's microprocessors, I'll probably try that one.
Like Michael, I skipped the M240. I didn't like the color very much, and now – many many months later – when there's a firmware fix and the waiting lists are shorter, it seems to border on obsolescence. I'm thinking of the A7r as a temporary vehicle for only a few M lenses, until there's a high-ISO M360 – or whatever comes next.
Kirk