Paul,
You a left or right eyed guy? If left eyed, the Leicavit will be Heaven because you no longer have to move your eye from the finder to advance the film. In situations where you want to keep your eye (and camera of course) on the scene and be ready to shoot potentially in sequence, the trigger winder is very nice, because the frame advance really becomes an afterthought. I never found that the wind motion threw the framing around; quite the contrary, in fact. That's for me as a left eyed shooter. The added height and weight of the winder is really pretty minimal, and it's not as if we're carrying M's in our pocket anyway.
Al, I often did have the same thoughts with regards to impalement by the trigger due to an unfortunate fall. But it could be used offensively if needed, as well, so I think the risk/benefit there is pretty much a wash.