I have always used PCM in my gassers. I use Futaba and have used just about all their receivers at one time or another with out problem..
I never set up with PPM to find small glitches and then change, and I don't have problems. I make sure of a good range check prior to first flight and then every time I swapp something or fix something I check again..If no fixes then at least every couple months..
I think set up is the key, and that is where people run into problems. I try to use quality accessories (sp?) only and I have run into problems when trying cheap parts. Also component seperation is a must, especially on electronic ignitions, I have seen too many flying field sessions spent trying to figure out problems with the radio installations. If you have room to seperate the engine components (ignitions, glow systems, smoke pumps, etc) use it, and don't run a metal throttle cable over the receiver or antenna.

You will get it right eventually

V-Snap

Good Luck