Mostly I use it to keep track of braking points. There are a couple of tracks where it seems to be a little too conservative (I don't need to brake that early for Laguna Seca's first corner, for gosh sakes), and at Tokyo the recommended gear seems flat-out wrong in places, but for the most part it serves its purpose well. Much better than just throwing the car through the turn and hoping it doesn't break loose, anyway.