After reading the exact opposite of my experience re the a7r, and always respectful of strongly presented views of others who 'know their stuff', I just reviewed a good sample of fully worked RX1 and a7r/FE55 images, all shot handheld at shutter speeds of less than 1/80s, both in RAW and final jpeg forms.
So, a real world, real shooting examination rather than 'looking for problems' which I feel is the main priority of net forums these days. Not restricted to Sony, of course, it goes on for all cameras. The perfect camera is due in 2050 for those with the time to wait - I don't.
I looked forensically at around 25 images of the same subjects from each camera, shot concurrently at/near wide open in LV ~1-5 by swapping these two cameras (done in one 'stealth' sweep for total silent shooting (RX1), the next for a different perspective (a7r) when, if I get sprung, I already have a good result from the RX1. I rate both lenses very highly, both are great at f2-f2.8.
One camera hopefully all can agree is a fine hand holder; and the other camera is almost unworkable according to many, or workable only outside this demanding range of s/speeds - which all of us would work to avoid whether the camera was a Nikon D810 or Sony a7r or Mamiya 7II. I have read from some that you cannot get a good image at all handheld at any s/speed with the a7r, or the image degrades so badly it is only the equal of 24Mp, or less, so why waste your time?
What this review revealed is that the a7r images - almost without exception - are preferable in their impact and aesthetic appeal. They are much more than 'sharp enough' regarding fine detail rendition of close up (but finely detailed) statuary and murals.
What I see is that the boost in tonal gradation and detail (and resulting 'sparkle' and subtlety in colour tones) present in a7r images is more important to the outcome than the better hand holding of the RX1, which benefits from both a leaf shutter and shorter FL.
Yes, it surprised me too, I had thought the RX1 was the bee's knees up to Feb this year, but now I would certainly prefer an a7r fitted with the RX1 lens/shutter for the 35mm FL! Outside in more normal light it is no contest, the a7r just walks away in '1/2xFL+' conditions, with the 55mm I see animal tracks in snow at 2000 metres - handheld. Posted not to convince, but as another data point for readers, cheers.