Definitely worth the wait.
The combat system is still as addictive as the system in Kingdom Hearts, but with even more features, the most noticeable feature which is the " Drive " form. You, as Sora, will be able to fuse with either Goofy and Donald. The combos are still similar to KH 1, starting with a 3-hit combo, but as u progress through the game, the 3-hit combo will actually start to increase more and more. Eventually leading to a combo which finishes your opponent in mid-air.
The graphics are good, i guess. The models are environment are alot more polished as compared to KH1, The FMV's for the game are awesome, i've gotta admit. Square Enix have made the best out of Playstation2's graphical limits.
The sound is alright. I thought there wasn't really any improvement in the sounds, except for the voice actors.
It may take quite a time for first-timers to actually understand the game. Considering that KH1 and Chain of Memories are deeply linked to KH2, so i really recommend to play the earlier versions first, or u may just be left clueless even after playing much of the storyline.
Still, even though there are flaws in this game. It's still a masterpiece and still very loyal to the storyline as it's a sequel.
Great job, Square Enix =)