I was just thinking that it might be hard to generalize something like the topic being discussed here. It's obvious that some are having problems where some others aren't. Perhaps the acceptable range within which these controllers must perform to pass QC is kind of wide.

I have five MM controllers. On a couple, I've had problems with the bec giving me headaches with my radio. I don't know that all would have given me problems. I just went to external becs so that I wouldn't have to worry about it.

Of the controllers that I have, three will run on 5S and two won't do anything when I put more than 4S on them. I don't know.