Don't know what to say.
This is the first "true sequel" to a Final Fantasy game, it's just too bad it had to be part of Final Fantasy X.
Gameplay: The Gameplay goes back to the Active Time Based combat from IV to IX. So that is a some what of a plus to the game, but after using Final Fantasy X's battle system I did not want to go back. Also I don't really like the Charlie's Angels themed setting.
Graphics: They are a little bit improved from Final Fantasy X, but in some places it actually looks worst. The majority of the game looks awesome, but they had very few CG cut-scenes, which are the star of the Final Fantasy games (at least from VII on up)
Sound: This is a first (main) Final Fantasy game that does not have Nobuo's musical genius, but despite that it is still very good. The biggest blow to the game is the opening cut-ccene's Britney Spears themed song. not the way I want to start off my Final Fantasy adventure. I'm sorry to those that do, but I don't.
The only reason I can say to play this game again is to get everything so you can unlock the 100% ending. There isn't any other reason to play it again. So if you played it once and got everything. You're done with this game for the rest of your life.