I have had all of the GRDs. The GRD II was my first. Functionally I never found the II to be limiting. Perhaps (likely) I dont push my GRDs as hard as others, so it rarely let me down with failing to focus and the exposure was generally spot on.
What I do wonder is IF my II was out of alignment in the lens. I find other people's images sharper than mine ever were. I never really noticed it while I owned it, but since I have seem many a II image that look a lot better than mine. I even tested it once on a tripod. I should have perhaps returned it for service.
Have a look at this group in Flickr - https://www.flickr.com/groups/grdigital2/
This image in particular looks tack sharp and nicely exposed - https://www.flickr.com/photos/s681111/1 ... rdigital2/
Perhaps I got a bad example with my II?
As Richard mentioned, I believe there was some NR applied to RAW files on the II and it could not be turned off, only set to min.
IMO the III was a big jump forward. My III yielded sharp images.
The LCD on the II was much nicer IMO than the I.
So I think the II is a fine camera, if the price is right, just make sure you get a good one!