I have both (at least for a little while longer . . . the XPan is in the process of being sold). I wound up using them in very different situations; M6 - available light portraiture, XPan - group portraiture outdoors. The quality on the Xpan 45 lens is spectacular. They are very different beasts though. I am surprised that Fuji/Hass did not design a 50/2 or a 40/1.4 lens for this camera just to cover the 35mm format. Oy, they would have had a KILLER ap then. As it was I kept reaching for my Leicas because of the speed and handholdability of the lenses (and, really (and this is the point), the kind of photography that I do). I think it really comes down to personal style and the "frame" you put around objects/scenes in the world. If I were travelling and had to choose between the two, I would take the M6. Fewer things to go wrong, full functionality with a dead battery, no need for a tripod to frame things carefully. And ultimately that is why I decided to sell mine: so that I could plunk the $$ down on something that I will use more often. Happy snaps.