My racing partner and I split the cost of one earlier this year. We are both going faster now. If nothing else, it's great for choosing among different propellers. Some make the engine sound terrific, but don't improve the airspeed. Others go well in the straights, but bog down in the turns. All this is useful information.

I like it better than the radar gun because you don't have to stand under the flight path, and the readings are not affected by wind.

Duane