An interesting thing I notice with the A7r. For street I'll leave it set to shutter priority at 1/500th. Doing the same on the Fuji X-E1, the camera would first select a wide open aperture, then start bumping the ISO upwards to maintain 1/500th. On the A7r it will open to f4, then bump the ISO until it hits the max, then start opening the aperture up further. This is pretty handy for street shooting as it ensures you don't end up with too shallower DoF.
Final observation, I think the A7r is the first camera I've owned which not only has quick enough AF, but intelligent enough AF for me to raise the camera, focus and shoot in one motion without breaking stride, and it nails it almost every single time. I could never do that with the Canon 5DmkII, Olympus E-M5 or Fuji X-E1. (via Flickr http://flic.kr/p/iyqyGn)