The first thing you notice about this über chain is the price, yep £125 is a whole heap of cash (though a 1m long version is available for £99). But for that you're getting a whole heap of lock; very weighty yes, but strength-wise it's simply one of the best. The double-locking untwistable padlock is superb and the hardened steel links are incredibly strong.
The first test did little or nothing to any part of this lock and after five minutes we were left with blunted tools and tired limbs. Out came the power tools, and just shy of a minute and a half we'd got through a link, but the noise and commotion this created would draw a crowd unless you're silly enough to park your bike in a cave. Kryptonite do things the American way, big and brash, and they're a world superpower when it comes to bike locks.