I must admit though strife has a point, while "host quit" is a major annoyance, for a console game COD4 had a fantastic match making system that 9 times out of 10 delivered a flawless experience up to the 18 player cap. I'm not saying that its perfect or a match for dedicated servers but for a console game it was pretty good.
lag and poor reg are much harder to notice on a console with sticks and auto aim.