i was just about to ask this same question!! please throw in some of those j-stick or japanese standard ball top sticks in there as well.
Here's my $.02: i've only handled the ultimates and competition. IMO, the ultimates suck and the competitions are good for fighters, hehe...now i've never installed a ultimate into my cp, but from messing around with it, it seems it likes to click/snap/pop into the 4 way positions and you would then need to pull it on. the competitions seem to have a smoother transition with no clicking except from microswitches. the ultimate can also double as a 4way since you have the option of installing a squared piece onto the end of the joystick which makes it touch the switches, like a 4way posing as a 8way.