RE: 2.4 - Why Are They Failing?
I only have 2 2.4 GHz radios, one for the Park Zone micros, and one for a Fly Zone Albatross. I would so far say that to date, I have had no more radio problems than with 72 MHz. That's basically since I've done far more flying on 72 than 2.4, so I'm basically estimating failure rates of 30 years flying on 72 vrs about 1 year on 2.4. That's also includes admitting that most "Radio" or "Interference " problems I've had in those 30 years were actually dumb thumbs or ignoring things like obvious low battery warnings, switch failures, things like that. Maybe 4 actual cases of interference, and maybe 8 of actual radio issues. I have had a problem with my PZ Micro P-51 because the "Brick" (said I've been doing this a while) broke free of it's mounting in the plane. That is, the AR6200 is mounted with 2 or 3 dots of some kind of white adhesive to the plane fuse. I repaired this with 4 drops of good ol' Ambroid. But, the last time I was flying the Mustang, the motor just basically turned off, went into a roll, then dived into the scrub. No damage done, and when I checked, everything worked fine, including on a ground check from a greater distance. I've had 8 good flights since.
Nothing man makes is 100% reliable. One my jobs in the lab where I worked was to run RFI testing. We went from about 40 Hz to 10 GHz, field strengths to 300 V/m (much higher than most commercial products need to be tested to). It was not unusual to find a problem, test a couple times in a row, then call the design engineer over and be unable to repeat it in front of him, but as soon as he was gone, have the problem return. Or have a problem one day, and not have it another. RF is almost an art and manipulation of black magic as it is a science.
2.4 is probably more intereference free than 72, but not absolutely.