The Sony RX1R is on the way for testing. The RX1R is the same as the Sony RX1 except that it omits the anti-aliasing (optical low pass) filter over the sensor, for sharper images.
I like a good grip on all my cameras, and the Sony RX1R feels unstable in the hand due to its lack of a grip, so my preferred solution (as on all my cameras) is a Really Right Stuff L bracket.
For field use I like it as shown with all three parts: and excellent grip along with the L plate and base plate for tripod mounting, and all the parts protect the camera from scratches and bumps.
The bracket consists of a base plate along with optional grip and L plate. So there are four possible configurations: base plate only, base plate + L-plate, base plate + grip, all parts. Reconfigure with the supplied allen wrench.
Update: the grip is for sure and solid, very nice.
Full BRX1-set (all three parts): 146 grams.