I leave my 360 on for days straight and have had it since launch... never had any problems. The problem is dumbasses standing it verticle on the carpet which covers up its largest vent, what do you expect to happen?
Xbox servers are much better, and the services that xbox live provides are worth the less than $5 per month. Sorry, but having to pay for xbl gold just isnt a knock against the 360. You like your PS3, great... there are others that do as well? You hate the xbox, great there are millions who love it! Opinions will varry and no one is wrong.
Here's some nice little statistics for you though
http://nexgenwars.com/