someone tried to steal my commuter a while back. ABUS u-lock to a city bike rack. they cut through one side of the lock completely, made it about 1/3 through the other side of the U, then was scared off by either passers, building security, or the electronic alarm on the bike flashing and beeping a skull on the screen at them, not sure which.This is the most overused dismissive comment on locks ever. Most thefts are unpremeditated and not by career criminals. Nearly always someone takes advantage of the time we leave our rides unlocked. Sure, New York City and its ilk have high crime and bold thieves but in every city, I've lived in with bicycles, 7 cities, and 6 states, I always lock and leave in the most secure spot possible and never lost a bike. There's no substitute for a decent lock.
in any case the robust lock (requiring two cuts with a grinder, not one) saved me a lot of hassle.