Also my unit gets warm with constant use (volume between 40-50) but not so hot as mentioned by Amir. It does not have so much space to breath (see picture below, I know it's ugly but you know the importance of the WAF...) but it seems more than enough for daily usage.Hello from Finland!
Interesting results... Are you sure that this particular unit was not somehow faulty? You mentioned that the unit gets very hot. This sounds a bit strange to me, because I've used this receiver for about a year now and it really does not get hot at normal living room use. Warm, yes, but never hot. I have disabled all eco functions, of course, so they do not explain my receivers "coolness".
Good job with measurements anyway. Very interesting to read!
(Sorry for my poor English.)