Loved using her in battle. The throwing spikey wheel thing (yeah I can't bothered to find out what those are called) is a pretty cool weapon.
As for her as a character......hmmmm. Bit annoying and she doesn't really have much input into the story.
Although I guess that could just be cos they wanted her to remain optional (although it was insanely hard to miss her). That's what FF needs to bring back: optional characters.