i had noticed after about 3 hours of decent volumes it gets hot to the touch, but i also have it about 2-3 inches from the wall, and at the time no feet, so it was getting almost no air flow.
I have since put four decks of cards under as tempory feet (hey the best i could do in my dorm room) and i had a small 120V fan that i put over the heat sink that i turn on when ever i know i will be pushing som serious db. I have periodicly check the heat sinks and noticed that it isn't nearly as hot as it was.
So my best suggestion is get it as much air as possible, even though that might pull it away from the sweet spot.
