What about Heat?
Nobody has mentioned how hot their receivers are getting.
My Mirage speakers are rated at 6 ohms with an efficiency of 90.5 db in room at one meter. I also have them bi-amped in a 5.1 setup. My receiver gets pretty hot, hotter than my previous HK AVR 85, and even hotter than my Pioneer SX-1250. While watching movies when the little ones aren't around I'm typically having the volume at -18 and that sucker gets hot. Not hot enough to fry an egg to too hot to touch buy pretty warm. I would think it's the excessive heat generated driving difficult loads that will eventually catch up with this receiver. I know Mule, get an outboard amp.
Comments?