I'm researching this very thing too.
Right now, I'm wavering between the Pioneer Elite 92TXH and the Denon 3808ci.
In my reading from AVS (

I know, I know!) and other sites, owners have complained about excessive heat output from the Onkyos. In addition, there are lots of anecdotals stories of Onkyo's reliability not being good.
My personal experience with Pioneer Elite (CRT HDTV) and Denon (receiver and DVD player) are that they have both been absolutely flawless in reliability and tops in performance.
I'm going to read and compare in detail both owner's manuals this weekend.