Watched the whole thing in a confused state, then saw the link to the behind-the-scenes, then sporadically watched some parts again. And I still can't believe it's actually stop-motion.
I've animated for quite a few years (though just 2d and pixelated stuff in Flash), so I'd like to think I've develloped a bit of an animator's eye. But that eye still tells me: 'nah dude, things look way too pretty, and the camera & characters move way to fluidly to be stop-motion'. Not just because of the framerate, but the whole movement of the characters.
Especially early on, in that super crowded scene, even all of the insignificant looking background characters move so organically, and just so many of them, moving around the place.
And don't even get me started on the action scenes, with all of the tumbling around and crazy shooting about, wich I think you really got crafty with, customising those mangled and bent arms for the more crazy acrobatics.
I basically went in my head, like Vegeta being a little bitch throughout 2nd half of the Freeza saga, going: "uuurgh, it can't be, that's impossible! He must be a super *something*".