I got one to try since I ride at higher elevations on my TE300. The bike already ran pretty good, but this did add a little more performance. It feels more crisp. Considering it isn't much more money than a stock compression head, it is a good deal.

Excellent results, I ride single track at 7,000' + elevation. This has proven to be a very good addition to an already excellent machine. Gettin a two stroke dialed in at high elevation is no easy chore. The HC head has helped alot. Throttle response has increase considerably as well as usable tork. I am getting much more carry out of each gear. "GREAT PRODUCT", at a reasonable price.

Definitely improved low-mid power. I ride at sea level a mix of tight single and fast open trail.
Best bang for buck mod I've put on my 300 since the JD jet kit.
Saves alot of clutch grabbing when you're too lazy to change down a gear exiting corners.

Definitely increased power low to mid and I would say slightly on top as well. The only complaint I have is I now have detonation when letting off the throttle. I run 92 octane pump gas and never had this problem before. I have attempted to add an octane booster to help but it has only helped slightly. I plan on running some AV100 to see if that solves the problem.