when the pop of death appears.
Which is not as often, I have to believe, as that one thread over at AVS suggests. With all the SR5004s and SR6004s sold in the Netherlands, I've only read about one or two "pops".
One good thing I heard about them was about the awesome quality playing songs. I don't know if the reviewer has an unbiased opinion but that was clearly stated on the review that the Denon and the Onkyo were no match in terms of sound quality while playing music
Those are just the kind of reviews you'll have to take with a big grain of salt. The differences in sound quality between modern, well-designed receivers are negligble. Base your decision on something else.