RPGs in general have little replay value unless they pull a Chrono Trigger or X-2. Once you've done everything there is usually no point to replay them unless you liked the plot.

I usually replay Rpgs because of this sentiment cause I think of playing through them as though I was reading through a book again. With this sentiment I would say XII does have replay value cause I did like its plot and cast and also because the game has been gaining some odd notoriety as being more amazing with each playthrough cause you can notice more of its intricate detail. This of course is just my opinion.