Oscar has a good multi page review on each type of happs stick.
supers allow you to spin the joystick smoothly in a circle... great for many games... but sometimes you want to know your going diagonal.
Competitions are great, but square motion. You can push the joystick diagonally up and fit it into a slot and it wont move. Great for fighting games, but not nearly as nice for other games.
Ultimates I've never heard a good word about...from someone who has more then one joystick. I have a few competitions and a few ultimates. I put the ultimates on player 3 and 4 on my control panels since the kids usually use those. I think they are cheap competitions.
But these are only the happs models...