I tried playing on-line when it first became available, starting with NCAA '04, and my experience was really bad. Almost everyone cheated. I mean seriously, how pathetic of a person do you need to be that winning is so important that you need to cheat in order to do it? I mean when I played on-line there were guys beating people 100-3, 77-7, 84-10, etc. Five minute quarters at the All-American level you are not going to beat someone 77-3 without cheating your a$$ off.
When I did find someone who didn't cheat, as soon as it was clear he was going to lose he'd leave the game by either resetting or causing the screen to freeze by slightly disconnecting the ethernet cable; after about 5-10 minutes of a frozen screen I'd get frustrated, hit the reset button and would get the stat as a loss.
Another thing is that these guys take teams like #1 USC, #2 Texas, #3 Florida, #4 Oklahoma, etc...beat people and then act like they're something special. It's easy to win when you're using one of the top 4 or 5 teams.
I'll challenge, and whip, anyone on NCAA College Football if we're playing side by side on the same console.