Thanks to B&H Photo, I was able to test the Ricoh GXR with the Ricoh A12 Mount for Leica M-mount Lenses.
The Ricoh A12 Mount for Leica M Lenses is a mount with a 10.7-megapixel APS-C sensor with no anti-aliasing filter, for bitingly sharp results with Leica wide angle lenses. Sharpness does not suffer from ray angle issues, becuase there is no thick glass over the sensor.
See my gear page for links to those items.
The sharpness is stunning and would put most any DSLR to shame in the 12-16 megapixel range.