6 hole vintage is easy to use, but can go out of tune in heavy tremolo use, not so bad for those wanting hardtail feel since you can always block it, good for guitars routed for trem but doesn't want trem.
Wilkinson is a compromise, they are relatively easy to adjust and adjusts a lot like a 6 hole in many case. They have good tuning stability PROVIDED you use a locking tremolo and graphite or roller nut. However they are not available in steel block that I know of (at least not from Stewmac, probably someone on ebay has a steel block version) for those who must have one... callaham doesn't make one either so a machine shop is the only choice if you must have one.
Floyd provides the best tuning stability for heavy tremolo use, so you can do that Joe Satriani dive bomb or whatever (but a really good guitarist could do that on a TOM les paul so...) however from what I understand they are a pain because you gotta change one string at a time or else something goes out of whack. Also retro-fitting it to a guitar requires heavy modification to the guitar, most likely de-valuing it if its a Fender or something. Wilkinson fits on an American Fender without any modification.