I don't passionately hate Cait Sith, but he could have been developed a lot better. Some suggestions:

1) Ditch the Moogle. And fast.

2) At least 4 limit breaks (it would be in line with his fortune telling ability to fight with tarot cards in a way similar to Death Dealers)

3) Gambler-type weapons like darts, razor-edged cards and daggers. Anything but the silly megaphone.

And Reeve was seriously underdeveloped in the game.