Thats unfortunate for you. Because, going all the way back to my first Mac, an Apple IIe back in '84, up to my current Mac Pro, and my wife's iMac, I've had a total of 11 Mac computers. And, the only one to ever give me any problems was the G4 Cube. But then again, who didn't have problems with that thing.
I've yet to hear anything about "frequent" problems or anything like that. There were some problems with heat in the Mac Books and MB Pros, but those were solved with firmware updates. We've now had 3 Intel Mac as well. And, even after that big change, things are still great. If not better. So, I'm sure there have been some problems out there. No company is completely deviod of problems. But, nothing widespread or all-encompassing. Very nice machines.
Hilg