Kryptonite locks are widely recognized as some of the best bicycle locks ever made. Don't believe me? Here are a few reviews from loyal Kryptonite customers:
They give you 3 keys but one of them broke right away, I think I stepped on it when the lock was laying on the ground. I am using the spare keys that shipped with it.
While I'll buy Kryptonite again, good product, they need to make stronger keys.
The good thing is that the New York Lock is just not going to fail, period. Your bike is going to be where you locked it. Downtown NYC, Bronx, wherever. One of the lighter models is probably good enough to meet most needs and is more transportable but this baby is made for New York City.
I have seen complaints about the keys but they don't seem to be a problem. The lock turns really smoothly so I haven't had to deal with the flimsiness of the lock key. Just make sure it is in all the way and turn it gently. :) Great U-lock, finally no worries. An awesome combination. I leave the lock at school due to it being heavy.
Occasionally, the lock does get stuck a bit, but if you throw in a bit of oil or lock grease or whatever, it works fine again.
I am very happy with this bike lock. Also, it doesn't weigh that much, and the peace of mind you get by using a U lock over a cable is priceless!