I have not had mine long but so far I am enormously impressed. Its certainly not for everyone, but now I have it set up how I want it and know what to change to achieve a given end, its tremendous.
I use the optical finder all the time except for close ups and there is therefore no lag issue to contend with. Just frame a touch tight because more is captured than seen inside the lines.
Last night I shot some 3200 iso frames, wide open at 1/10 or so of a second. The results astonished me. Much easier to hand hold at slow speeds than my 5DII and the high ISO is right up there... The images looked very, very good. If they improve on the X100 and bring out a fully 'pro' aimed version with interchangeable lenses, Leica needs to be seriously worried. This little gem has not erased my hankering for a M9, but there is no doubt about it, for my purposes it is a better walk around camera by virtue of being 'good enough' and considerably lighter, smaller and more 'losable'. All I need now is a version that will has a 28, 50 and 75mm or similar lenses and with better manual focus 🙂