I use a whole bunch of different cameras, including m4/3. Despite what NEX people will tell you, the small-size m4/3s are smaller, usually, if you include the lens, and as a system, m4/3 is distinctly smaller than a NEX equivalent. (Panasonic also makes some larger m4/3 cameras, like the DH2.) The main problem (if there is one) of the m4/3 cameras is that both makers are using older-generation sensors. If they were using current-generation sensors (like those in the D7000 or the K5) then I think m4/3 would probably be a distinct step ahead of the Nikon offering. Nikon for the moment may be just as good as m4/3, but I don't believe that will last -- there's too much difference in sensor size. You can, of course, ask whether you really need much more performance from the Nikon -- I suspect it will make very good prints up to 22" or so, especially for personal use. I find the high-ISO performance intriguing, and if m4/3 continues to trail in sensor performance, I may try the V1. It's the small size of the systems that I'm after...Another thing to note, m4/3 offers a substantial lens system (including even fisheyes, and a zoom that goes out to a 600 equiv) that we see with neither NEX or, as yet, with the Nikon. I'm a longtime Nikon user, and I have to say I don't entirely trust their performance in producing much-needed lenses.