Zidane is the only Thief you have in FF9, plus he's a strong physical attacker. His Trances are very powerful as well, since Grand Lethal does 9,999 a lot. How does that suck?

If you stole a fairly good amount of stuff from bosses, Theivery already does about 1000 by the middle of Disc 3. At least, that's how it was for me anyways. Besides, it has an 8 MP cost. What did you expect?

But his greatest ability is that he is the fastest character in the game.