As I understand, the 6 and 7 models run cooler than the 5. I suspect they got tired of pro reviewers mentioning it.
Hot? I couldn't keep my hand on there for more than a few seconds, without more than "slight" discomfort. That, combined with a plasma TV, virtually dictated that I turn on the air conditioning to remain comfortable.
My Pio SC-07, which has the same rated output (140 W per channel), runs much cooler.