I've the M8.2 (+summilux 35mm, elmarit 24mm, ...) and it drives me nuts. I bought it for street and travel work, but I always end up in situations where 640ISO is not enough (any ISO setting higher is absolutely unusable) and of course I'm spoiled by my Nikon D3 high ISO capabilities. Also the default color/tone is magenta-ish and not really pleasant (luckily Aperture helps a lot correcting this). Bad moire, due to no low pass filter. The batteries are archaic and last only a few hours (and during a recent shoot at -8C not more than 15m). Of course, it is beautifully built and the lenses are the best. Therefore I jumped on the X-Pro1 (hopefully finally coming this week) in desperation, innovative sensor with top high ISO capability fixing most of the M shortcomings. I also ordered the M adapter so I can use my M glass. I am sure Fuji will address most shortcomings in firmware updates (MF focus peaking, etc, etc). Wait and hope.