I think there is some confusion regarding the lock on a Kryptonite U-Lock. The Kryptonite I have does not have a round, barrel style key. It's flat, but knotched in a squarish pattern. It would be pretty tough to pick. Angle Grinder? No problem.

FWIW. Kryponite did/does make a line of uber-cheap U-Locks for the big box stores. They have no where the quality of the Kryptonite lock sold through bike retailers and most on-line places. Those locks are easier to break and pick.