Received the Zeiss 55/1.8 about a week ago. Been running it through it's paces.
IQ is pretty darn good when it hits. AF is still slower than I would've hoped. Accuracy is good enough when it is fast enough to catch what I'm shooting. Still getting a decent amount of misses.
Re the size of the a7r + 55, I have found that it is not much of a size/weight advantage for me. Much like I thought prior to getting the combo, if you're going to go small/light, go all the way. The sony combo is somewhere in between. With the 55 mounted, the dimensions do not leave me thinking, "wow, this is so much easier to lug around than my 6D." I had an old nifty fifty around and I decided to do a side by side comparison of size. The Sony rig actually protrudes significantly further due to lens length. So going almost like for like with lenses, the A7r really doesn't provide a size advantage at all depending on what you're doing. It is lighter, but not to the point where I don't notice it. The only camera I have that accomplishes that is the x100s.
Also mounted some other lenses and found that performance was quite poor.
100L - exhibits some wacky behavior with regard to max aperture, AF is poo poo, overall poor user experience
Sigma 35 Art - AF is unuseable as expected, IQ is very good.
135L - Same experience as the Sigma and others
TSE 45 and 90 - Used both for slow shutter work over the weekend and got some odd flaring and artifacts. Will have to inspect the adapter and perhaps line the inside to reduce reflections. IQ is better than when they are mounted on my Canon bodies (as expected) minus the artifacts.
On another note, I am still finding that I have to shoot at much faster shutter speeds than I normally would with my other rigs in order to rid camera shake. I thought that maybe some of my initial shutter speed issues were due to having an adapter present which allowed for more slop/vibration. However, now mounting the FE 55/1.8, I am still finding that I have to shoot at 2:1 ratio for speed:focal length which is basically double what I'm normally capable of shooting at.
All in all, the keepers I'm getting are still great and I'm pretty sure it is good enough to stay in the bag......for now.
More to come.
Overall, I am still content with