TrackIR and Racing Sims?

Is anyone here using the NaturalPoint TrackIR (www.trackir.com)with
Racings Sims?

It seems to be geared more for flight sims (which I'm into much less
than racing sims), but has direct support for a few racing sims as well,
like GTR and LFS. (There may be more....) It also reportedly has
indirect support for GPL through the GPLShift utility.

I'm curious about how worthwhile this thing is for racing sims, how easy
it is to install and use, whether it requires it's own power (other than
what's supplied through USB), and whether it supports other racing sims
either directly or indirectly.

Any info on this would be greatly appreciated.

Thanks!