In the beginning of KH 1 and 2, you are told to pick a sword, a shield, or a staff/wand. I chose the sword.
I always take the shield and give up the sword. I suppose my gameplay is mostly defensive, I usually block a strike then just go in for a counterattack, then run away really quickly. I'm also pretty awful at video games, even (relatively) easy ones like KH, so I figure that with defense & magic I can get bashed around a lot with little penalty. Plus it said "a sword of destruction and ruin" and I like being a noble dude in video games. :B
Staff and Sword. I didn't know english when i started playing for the first time, and i actually thought i'd get to wield the two .-.
KH1:Staff KH2:Sword I'm really not sure why I prefer a magic build in KH1 when I play with a meele style in both games.
It's kinda useless since Thundaga can clean house in endgame anyway and no one should be using magic on bosses except to heal or Aero. I always take the sword and drop the shield. It forces me to play smart and gives me maximum damage output.
I chose the shield. Because it looked cool. I never cared about the little differences in stats it gave me.
Choose the sword, gave up the staff. Didn't EVER use magic since it Spoiler killed me three times in Kh1. Very upsetting.... KH2, I used the sword again. I like playing the offensive, plus You level up more quicker, unlike when you get the staff. Not saying I got anything against it!
Leveling rate is independant of what you pick. In KH1 that can be changed with the three "Tell me about yourself" questions. in the other games it is just universal. If it feels like you are leveling faster the only reason is that you are killing things faster.
I picked the Shield. No real reason, I just liked the "Power of the guardian" title they put in it's description. I felt a bit like a bad-ass after I got the Guardian Soul keyblade in KH2 :P