""It's my understanding when the receiver locks into "Fail-safe" you are not going to regain control of the aircraft. " - FALSE

Ditto with Barracuda et. al., that is totally not correct, yet it seems to bounce around this forum and at the fields. Barracuda explained the technical bits, so I won't go there. But I will say that PCM, or more specifically PCM's failsafe, did indeed save me a $3K plane.

I believe I mentioned this is another thread, but I went into failsafe while in the air because of an offending TX that was turned on and transmitted on my freq (I had the freq marker.) I went into full failsafe, which I had set to engine at idle and controls neutral. I was somewhat lucky in that I was finishing an outside loop from the top and was pointed up at about 20 degrees up when the offending TX was turned on. While in failsafe, my plane followed a nice arc, at idle.

As one can imagine, I yelled some not so pleasant words pretty loud and the offending TX was turned off. I instantly regained full control of the plane and finished my flight without incident. The time I was in full fail safe was only when the offending TX was on, about 5-10 seconds.

With PPM, the offending PPM TX would have caused my controls and throttle to go nuts, probably put me in some funky spin. Even if I regained control before I hit the ground, I'd probably be pointed straight down and spinning, which takes altitude to recover from.

With the PCM, the plane was very well behaved and recovery once the failsafe releases is a no brainer.

Without flying under the exact same conditions with PPM, it is hard to say exactly what would or would not have happened. However, I am 100% convinced that there is NO way without the failsafes I'd still have that plane. Notice I said "failsafe." You don't need PCM to get the failsafe anymore. But as pointed out, there are some signal quality issues inherent in PCM that make it a bit better than PPM even without considering fail safes.