I've always thought of them as an easy way to tune up your engine in a safe way without big engine changes. The advertisements look very promising. But I don't have any real life experience with reed testing.
There was a reed test done on Scream and Fly a while back and the Boysens made OK power BUT quickly faded after several pulls and the others didn't..
I like and run nothing but the TDR reeds because of their 100% success on my rebuilds..Its just one thing I can remove from the failure equation on customers motors..