If you genuinely enjoyed X, then definitely pick it up. It by no means does any disservice to the original. It has new content from the international version which us Yanks never got to play, including an "expert" sphere grid which emphasizes slightly more on path planning than the original.
We get to play them, only after our 10 year punishment and our crying over it. :P
Except for 12, like SE would ever let us have that. Even if they did they would remove some of the cool secrets that they left in the game, like that bow that is the strongest weapon in the game.