Given the linearity, the crappy plot, boring characters, and even exploring Pulse so far being about as much fun as almost landing on the family jewels after a failed attempt at a 40" box jump last night, any chance at the game having any replayability would hinge on the battle system. But since you get absolutely no control over even party setup for the first 20+ hours it means that fully half the game will be the exact same as the first time through. Add in the fact that the battle system is still pretty shallow even when fully fleshed out and that you need a balance of all the roles to really succeed and there's no reason to play again. Even using a different party won't yield a drastically different game unless you like leaving out roles you may occasionally need to either avoid battles taking half an hour, or which are required at points to save you from instant death.

Without a better battle system, more exploration and a better plot, I can safely say I will never play this game again after I muster the will to finally trudge on through to the end.