I have a friend who is a custom installer. He hates using Onkyo too because he has to replace them more often, which makes him look BAD!
He told me one time his team had to replace THREE Onkyo AVR for the same client! His client insisted on Onkyo because it was cheap. The client finally gave in and agreed on Pioneer.
Pretty much the WORD around most forums is to stick with Yamaha, Denon, Marantz, Pioneer, and Sony for reliability. Onkyo seems to have the most bashing. Harman Kardon and NAD arguably come in second in regards to reliability, at least from a year ago.