I was sort of disappointed when I kept getting throttled by an early boss in the game, to the point of almost giving up. Then I thought that I might try teaming up with somebody online to make progress, and viola! First game I created was a full hour of kicking ass with some dude I didn't know. Unfortunately, since then I haven't had consistent luck getting games going online. To call it busted, for me, is an exaggeration; I've heard of the game dumping saves, and if that happens to me, I wouldn't hesitate to call it busted.

EDIT: A minute or two after posting this, my 360 froze after populating a list of custom games available for online co-op. Yikes.