Blue Cheese
Mental Patient, GOT Ward
I have heard of it, but I haven't really payed it any attention as I have the TrackIR.
A quick search reveals you will have a bit of work to do getting it to work, and it still won't be as good as TrackIR Pro (but should be on par with just the Track IR)
TrackIR Pro (with the clip that has LEDs on it powered by USB, which is what I have) still retains the edge. However, if price is your driving factor, then it would appear that TrackHat is deserving of your money.
I've decided to save up for Occulus Rift, got a lot on at the moment regarding the house which is costing but I 100% will not be getting Trackhat as the customer service seems to be an issue from what I read, apparently they are really hard to get hold of. I'll swerve and save up.