My Dad has one, and it's just so so. The cameras lens is too narrow, so it has to be adjusted perfect or it won't get the shot you want. I've got the GoPro wide and it's sooo much easier to aim with the wide angle lens.
I have a couple buddies that run these. Here's a clip from the last race. Don't mind the first little bit of footage, I think the had some mounting issues. The video would probably be a little nicer, but he's still running a windshield.