I have the A7R and the 85mm f1.4 ZA lens, and utilize the LA-EA4 adapter. I can tell you that the 85mm lens is a great performer, and this combo works fantastically. The autofocus with the adapter is fast and spot on. The autofocus is accurate enough that no manual focusing or peaking are needed. The balance and feel of the lens, adapter, and camera is very nice, and feels comfortable in your hands.
The 85mm lens is excellent for portraits, with a perspective that I really like; I personally like getting a closer portrait, without necessarily getting real close to a subject.