It's very early days and I'm not a technical hot-shot on this stuff but, so far, I prefer the look of the images I'm getting with the SD Quattro compared to the DP2M. I've had a few prints done and, personally-speaking, they are a definite improvement. Interestingly, the guys at the lab commented favourably on the files and I hadn't mentioned what camera they were taken on.
All my pro work is done on Canon and, occasionally Nikon, but my personal work was mostly on film. The SDQ has made me change my mind, my film days are coming to an end!
Oh, by the way, I even like the sound of the shutter. Silly but true.