What are you using for your track days and/or race events?

I have a GoPro Hero, non-wide, and it has done well so far. However, the lack of decent audio and its ability to somehow kill batteries after 30 minutes is getting to me.

I've been looking at the POV systems, as well at RaceOptics. Both seem to use the Sony 480 or 520 line bullet cams, which seems to be the norm on most professional systems I've looked at.