No hotter than any other non-fan cooled amplifier I have used Brian...
So far

It gets to a certain temp but then just stays there and gets no hotter - mind you I have only used it in a smallish hall, with no people so I have not really run it at 9

for any length of time yet.
Can you link me to the review? I would not mind seeing it myself

or is it easily findable?
Dennis