Would my old G19 have fired out of battery? I dunno, but it never did while I owned it. I also never had to utilize Glock's CS, so I can't comment on that either.
But to your direct question, the things that caused me to switch initially like the grip size, capacity, etc have not changed.
It's difficult to say how I'd feel in your situation. This thread was very influential in my decision to switch from Glock to M&P, and almost a year and 10k rounds later, I am still pleased with that decision. With that said, obviously I have not had a catastrophic failure followed by a ****ty customer service experience. While I'm sure it's enough to shake your faith, I don't think it is a common enough occurrence to abandon the platform.