Back to one (my M3) for quite a while. Having two just seemed to result in one gathering dust, but an M is hard to sell none the less, I have found. I would like to re-buy my first M, a black M6, which would perfectly compliment my M3, in a number of ways, but who knows. I must have a re-read of the thread though, because aside from collecting them, I cannot see the utility in more than two M's, except maybe two film and two digital for combined film and and digital shooters, although even that seems quite a luxury.