The new Onkyo's have issues? Now looking at the ventilation requirements, I wonder if that could be related. Being THX+ rated they should be fine with 4ohm loads, like the 80's.

M80s VP180 4xM22ow 4xM3ic EP600 2xEP350
AnthemAVM60 Outlaw7700 EmoA500 Epson5040UB FluanceRT85