Wow... Your LHS doesn’t know Jack. PPM & PCM both work great on Gas planes. Many thousand planes have flown well on both. Most of the TOC/ Expert IMAC/Pattern type guys fly PCM not PPM, so don't worry about lock-out cr@p. Hitec receivers also have a great reputation in gas planes, often out performing the Futaba/JR counterparts.

The set-up and the precautions you take before you fly is what are important. It sounds like this guy didn't get that right either!