i think it comes down to playing style.. if you need to play "pad horsie" all day, get a floyd. if you only ever need subtle touches, or even just want the "refined" look that comes with a bigsby, go bigsby.
I like bigsby's because I think they look great.. I've got one on a 335 and it is just so cool looking.. although i'm sure some will disagree!
i think they look fantastic on SGs and smaller guitars too, but the arm is just in the way.
all that said and done, give me a hardtail TOM any day of the week.