My problem with the GBA player is mostly having to do with the B button being where it is and the control stick making dodge rolls possible only in your dreams. The opening cinema scenes just looked really awful on Player IMO, then again the GCN might have spoiled my vision with several of it's games (Baten Katios in particular <3)
0 Item cards and Spell cards are quite frankly TERRIBLE, you are much better off with a 7, 8, or 9. The reason being that they can take a while to have their effects go off, and they could be broken by ANYTHING if the card you were using was a zero card. Zero cards are only really useful if they are Keyblades because it is usually difficult for a boss to get in an attack if you card break them and hit them with your keyblade, while they can recover and attack again before your Mega-elixir restores all of your cards and resets your reload counter.
Kinda stinks eh?
9s are a good way to go in terms of card values, but do not forget that low number slights, like Ragnarok (Total value is from 7 to 9) and Ars Arcanum (1 to 6) plus the all 0s Zantetsuken
p), are still very good. Sonic Blade also (21 to 23 I believe...? *has had GBA confiscated*) does a heck of a lot of damage because it can slide through multiple enemies 6 times by pressing A at the end of each dash across the screen.
Also remember to place a prenium card at the beginning of a Slight, because cards used first in a slight or combo can't be reloaded, just like Prenium cards.
Just because slights eat up your cards does not mean you should not use them, Curaga, Sonic Blade, Ragnarok, and Zantetsuken are all life savers against the many late game bosses who move around a lot and attack very quickly (I'm looking at you Larxene).
...I don't think I can type anymore now since I was at Castle Oblivion, just before Axel, when my GBA was taken away a few days ago *sweatdrops*.