Hi SoftwireEngineer, My speakers are 102dB sensitive and 8 Ohms. They are very efficient but the Panasonic gets very hot left center, even if you leave the unit on with no speakers connected. I've talked to Panasonic tech support and he said it will run hot without a fan. He said the SA-XR57 has a new heat sink cross-bar to help out with that problem but I haven't tried the 57 model to confirm that.
The Panasonic runs much hotter than my Rotel analogs! The Rotels stay cool running and only sometimes hardly even warm to the touch, but these are 2-channel Rotel's not multichannel, as usually multichannel can run warmer. I was just very surprised how hot the Panasonic digital amp runs with all the advertised "no heat" marketing that digital amps get.
Anyway, don't take me wrong. The Panasonic is a very good sounding product, especially for it's price, enough for me to keep mine. I still like it. Panasonic did a good job. I was just surprised how close the Onkyo A-9555 comes in sound to the Rotel, but it still doesn't replace a Rotel, just much more so than the Panasonic. Digital still has the problem with not being able to give the round-airiness that some of the best analogs can give but I'm sure they will figure out how to in time, but that's been the big debate between the analog vs digital for quite some time now.
I think SiriuslyCold makes a good point, if someone is used to having such an amp as cooking an egg on it from how hot, then to those, the Panasonic might seem like it doesn't get as hot. I just don't like when poor designs allow for such heat build-up that doesn't have to be, it shortens component life. The problem is solved with the Panasonic with allowing a small fan keep it cool, then it runs very cool without any heat build up. So now my Panasonic does run very cool with using the fan. Enjoy!