Haven't had my bike stolen yet!
Got the large one, and it gets the job done. Yeah, its heavy, but what do you expect from a u-lock? My only complaint is that you have to be sure that the lock is tight and 100% flush closed when you lock up, or it wont lock all the way. Sounds like a minimal problem, (and I guess it is) but I always feel like its closed when its not so, it throws me off whenever I'm locking up. Solid lock though!