A lot of people don't understand the GXR concept, especially if you look at the DP Review forum. I mean, why mate a sensor to a lens when the sensor is going to be outdated in 6 months yet the lens will always be excellent and deliver the same quality.
They are quite right in a lot of ways, especially considering just how much better the Ricoh lenses really are compared to the competition. Also when looking at the relatively poor m4/3 lenses which just don't have the optical quality of a Ricoh or Leica lens. They look great because the camera software is great and correcting for most issues but not because the lenses are any good technically.
So at the moment you have the choice of going for the GXR and have excellent optics done by Ricoh or going for m4/3 and have great software fixing any lens faults in camera.
This picture is a great example of how poor optically the highly praised Panasonic 20mm f1.7 lens really is. The bars were all straight and from a 40mm lens I expect them to be straight, as they are in the JPG but not when looking at the RAW file.
At the same time I much prefer the image quality of the 4/3 sensor to that of the APS sensor in the GXR which is too clean and digital looking, here I have some noise and some character. I will never understand people shouting for less noise in pictures and who are looking or perfect pictures. Perfection is boring and looks fake and digital, there is no life or character in technically perfect images.