All Bibby's are constructed like the 190's last year, so less jib, more for charging lines and good cliff jumps! JJ is really a bit to short for a lot of people.. The 174 and 184 are not more jibby, they are just for smaller people :) But offcourse you could choose for a smaller length to be able to do more jib stuff, but why not choose the night train then? S7 is really more directional and again 5cm bigger but has a stupid big tip if you asm me..
You can mount Bibby's to what you like most, really charging more old school mount to get a directional ski or more centered so you have long tails for drops, they can turn really quick in trees and become very pivoty..