The jems pull up further because they're routed out behind the bridge.
(yes, by the way - a C is a P4 up from a G)
my rg550 pulled up to a B off the G string when set up properly. *(think 'the attitude song').
My BFP pulls up slightly higher than a C - almost a C#
Whether or not string gauge has anything to do with it, i don't know. *my UV and JEM are both strung with D'Addario .010s and mt RG had D'Add .011s.
I've never had good luck keeping them in tune with excessive bar use if they're not properly set up, so I can't stand behind what Rich says - maybe if Rich wants to elaborate further on his methods......
Floyd bridges break strings faster. *period. *There's a constant strain on the string at it's curving point in the bridge - every time you bend a note you're putting pressure/release on all the other strings at the bridge. *Lots or bar use compounds that. *Nice thing about the Floyds is that every string has two lives (sometimes three, if nec.) because if you leave enough string on the tuning posts when you restring it, you can just pull the broken string back down in wind it *up again. *This method requires cutting the balls off beforehand, *(:laugh

*Usually about 3 gigs into a set of strings, if one breaks, I'll go ahead and cut the other culprits at the bridge and reinsert them, so I don't have to do it mid-song. *My culprits are E's, B's and D's - occasionally an A and almost NEVER G's. *i've also found that i break fewer string in the .010 sets than in the .011s. *probbaly something to do with how much extra tension there is with the .011s.
Another unconventional thing i do to get further 'down' range from the trem is I put the short end of the bar into a clamp and pull the other end up - it brings the bar a bit higher up from the guitar, so you can push down further, thus a better 'spaghetti' effect, as Bob put it. *Just a bit of a bend will do just fine - don't go nuts! *Kevan doesn't like this because 'you can never bend two bars exactly the same'. *So of us don't care as much about sonsistency as others, i guess. *i just don't like the bar close to the body.
~kenny