The 7300 puts off a fair amount of heat, but no more than your normal receiver. It's giant size is due to it's HUGE heat sinks that run along the size.
The DCDi processor inside has it's own Heat sink/Fan.. so there is some actual active air movement from within the unit.
Make sure they offer a 90-day money back or something of the likes. My unit was damaged during shipping from OneCall. A screw was knocked loose and was grounding out the transformer. This was causing a pop and hum from the speakers when the relay kicked on.
I've been very pleased with my 7300 and am very happy with its performance per dollar. IN HIND SIGHT THOUGH, I wish I would have waited until this current generation (or next) receivers came out, so I could also have HDMI switching and full 1080i up scaling (not just S-Video, Composite and 480i Component to 480p).