I've used one. Hobby People is not bringing them in now, but the ASP is the same engine from the same factory.
Setup: Stock engine, 10/22GMA, 11x4.5 TT Cyclone prop, Thunderbolt idle bar long reach, .272" venturi, .156" Randy Aero NV Assy. I did use an OS .46LA muffler (for nose weight) and muffler pressure to a 4 oz Hayes tank, but the muffler doesn't seem to change much except the nose...the .46LA muffler (with baffle) is almost "electric quiet", at least from a distance. Launch at about 9.7k, and line length probably 60' i2i +/-. I got the airplane/engine from Mike Haverly; we figured it had at least 15 gallons of fuel through it, and it still did long strings of 1 flip starts...and a couple starts without the battery attached, so be a bit cautious. They seem to really want to run!

Steve