It sucks not being able to trust your preferred gear.
Without diminishing the seriousness any of those failure reports, I can't help but go into tech support troubleshooting mode and ask a million questions. As easy and entertaining as it is to say "NDSP is clueless and the QC is a turd", things generally happen as a result of actual causes.
I'd be curious to know how long these owners had run their QC's before they started exhibiting problems, and what, if any, variables were introduced before those problems began. If a QC fails in the first couple of weeks of operation, then it's possible/ somewhat probable it's simply a defective unit. (Like the first one I received.) If it runs for months and months and then suddenly doesn't, then something must have changed corresponding with that failure: physical damage, a firmware update, content (capture, preset, setlist) corruption, or some unprecedented, uncommon pattern of usage. (Notably, the last two explanations would indicate an OS bug.)
I had a brief spell (maybe a couple of weeks) after a recent firmware update where my QC wouldn't boot fully when I first powered up. (I think this was reported by a few other people as well?) I'd have to unplug DC and reconnect for it to fully boot. But I think the firmware change was coincidental (or only part of the problem); it seems more likely it was related to other devices on the power strip drawing a lot of current simultaneously. So I'd be curious to hear more about AC quality and power supply configurations being used by those reporting problems. Stock PSU or third party PSUs? AC strips/ splitters "upstream"? What else is on their boards that might be drawing a lot of current while the QC is trying to boot?
But most importantly:
what changed since the QC last functioned properly? Is the failure now unrecoverable, or is it intermittent. Do efforts to change the variables identified improve matters at all? Etc. etc. etc.
I hear ya. I'm driving myself crazy trying to decide whether to (also) be a FAS guy. Either way I'll keep the QC, but I'd prefer to "pick a lane" and get back to focusing on the guitar. I must have changed my mind back and forth 5 times last night alone. There are a few things the FM3 does better than the QC, but for the most part I can get them sounding very close to one another, and the QC is just so much easier to program, configure, reconfigure as needed.
The good news is that the comparison has me digging a little deeper into the QC effects than I had previously. For instance, the Modulated Reverb is more useful than I expected. (It might be a better stand-in for spring reverb than the so-called Spring reverb LOL.)