I bought 10 usgt motors. Tested all of them and was able to build 2 near perfect motors. Any advantage in spec racing is just that much bigger. The motors a little faster. Accelerated faster and ran cooler than a motor “just dropped in”. Since then I have learned ways of adjusting the motor that will get me results close to that perfect motor. It still takes 3 motors as there are some things that can not be changed.