In the end, despite its flaws, Kingdom Hearts Re: Chain of Memories is a good game and is really fun, provided that you have played other games in the series. The plot between floors is very deep, and even though Chain of Memories is not a numbered game in the Kingdom Hearts series, its events are integral to the plot of Kingdom Hearts II. The battle system is fun and boss battles will actually require strategy and planning.
If you skipped Chain of Memories the first time because you didn't want to play it on the GBA, you should definitely reconsider it now. Even if you played the original, there's been enough polishing done to it that it's still worth your time, especially since the whole experience is greater than the sum of the parts.