I'm buying a used xbox in 2 days and I was thinking of a good stress test for it. My idea is to drape a towel over the xbox laying on it's side and see if it holds up heat wise for a certain amount of time. What length of time would you say is impressive without any freezing, etc.? A poor performance? Besides playing it at the owner's home for about 30 mins, I'm thinking this could give me some insight. Opinions?