I have to say, after my first month shooting with the XP3, for 3 weeks in Israel on business, then France for two on vacation, Peter Poete in the aforereferrenced blog nails my experience so far. Ahead of release, I saw the missing rear screen with flip-down top-view LCD as ideal for me, and the submonitor as potentially the ideal solution for my tastes (more rugged and discreet = win-win!), but the submonitor ultimately is more about fashion than function. Backight it and connect it to Q menu, and we have a revolution... otherwise, kool try, but not a serious feature.
The only other things I can mention from my experience so far, is that the exposure compensation dial is way too easy to knock off previous settings, which got me many times (lock/unlock button like for ss dual would fix this), or stiffer clicks to move. Menu settings enable rich and deep tailoring, which when mapped to personal custom settings that can be named is wonderful, and allows me to fine tune my "voice" for more consistent results. They simulate shooting with rolls of film, where the digitization of such makes film changes immediate and easy. I still capture raw files with my Fujifilm JPGs, but found myself simplifying my approach overall by thinking in terms of rolls of film, 7 of them, based on Fujifilm emulations while I was shooting. Back in post, I may do some dodging and burning, clarifying and texturizing, but am shooting dramatically more SOOC, and thinking more about composition at the decisive moment, rather than "I'll fix it/design it in post". More time to shoot, view, and think about the art rather than technology.
The XP3, she can be mysterious and confusing at times, but her heart and brain is massive... we are enjoying each other so far.