I'm disappointed in myself. As a huge Kingdom Hearts fan, I still didn't beat this yet. I started playing it when the HD collection released, got all the way to the end (unlocked the last world). Then I started to grind for stuff to get the Ultimate Weapon and kind of got bored and quit when new games came out. Haven't went back to it yet. I really want to beat it, then play Re: CoM before KH 2.5 HD releases. Speaking of which, I'm disappointed we still don't have a release date.
That's exactly why I saved the grinding for items as the very last thing to do. It made all the optional bosses more difficult too, which was a fun challenge. By the time I saw and killed everything in the game, I started grinding and realized there was no point and it's so boring, so I quit.