As endings go in the series. It's one of the best IMHO. You actually get to know what happened to everyone. I would have agreed about the whole final dungeon being pretty rushed but after playing it again recently, it was a hell of a lot better than I remember it being. (SPOILER)Gabranth forever...

And shame on you Renmiri... I thought we discussed this

It's probably the second best ending in the series, only after FFI.

As for the game itself... it's probably my third or fourth favorite (it's duking it out with FFV at the moment) I'm afraid FFVI and FFIV will always be my favorites though FFXII did give them a run for there money.