I know no lock is going to last more than a few minutes under the proper tools and bystanders are going to be absolutely no help. I'm curious though if anyone has successfully gotten paid out on one of the guarantees, like Kryptonite's guarantee up to X amount of dollars. I have found an example of a guy in England getting paid, but it took a lot of doing since he was working through a secondary company based in England to get the U.S. based Kryptonite to pay out. Plus the thief took the lock with the bike, which is required to prove lock failure.
Conversely, has anyone had a bike lock with a guarantee fail and have their bike stolen?