I've always been a KH magician for three reasons.
1. Spells eventually grow strong enough to kill everything with a single thundaga, saving time in the colliseaum tournaments and sythesis item hunting.
2. Long range, hit and run abilities, plus a balance of tactics. (Having to hack and slash ALL THE TIME cuz your magic is too low to be of any possible use is boring)
3. When your magic isnt quite good enough at first, having low strength makes it harder more fun cuz it takes a lot more hits to finish anything off, especially bosses.
Though I admit to picking the sword the first time I played KH1 cuz I didn't know how much of an effect it would have on you. Too bad KH2 doesnt allow you to get more MP than normal by picking staff. I think it maxes at 140 no matter what cuz of the bonus level system. I want like 200 mana.