I used "round key" Kryptonite locks for twenty-five years. During that entire period, I lived and rode in "high crime" inner-city neighborhoods. Never had a bike stolen (stripped down to the frame...yes...stolen...no). So, I got good service from the round key locks.

The "flat key" locks were supposed to be "new and improved". And, they were free. Trade locks that are five, ten, and twenty years old for a "free" new lock...who could say no?

After using them for a few months, I am a tad disappointed with the "flat key" locks. The rotating plates are too easily put out of alignment, making it finicky to get the key in and out. But, with practice, unlocking them becomes routine. Still...bending down over a bike rack, late at night in so-so neighborhoods...who wants a finicky lock?

All of the fuss about round key versus flat key has been a distraction from the REAL weaknesses of most locks. Most bike locks are waay to easy to open using cutting methods or leverage methods.

The best U-lock is the Kryptonite New York lock. It has a "dual bolt" design that forces a crook to cut both arms of the shackle. It uses high grade steel that resists cutting. The quality of the steel makes the lock highly resistant to leverage and prying attacks. Design features that ought to be on every "serious" U-lock.

With the time and money invested in "round keys versus flat keys debate", Kryptonite COULD have extended the "dual deadbolt" design and the cut-resistant shackle design to lighter, less expensive models. There COULD be a two pound "Mini" U-lock with those features. Instead, in 2005, most lower priced Kryptonite locks featured mediocre shackles with only ONE locking foot. Such designs can be defeated by the methods "real world" crooks use...and those methods don't include BIC pens.

Hopefully, with the "round key" debate out of the way, Kryptonite will take care of business with REAL improvements in its bike locks:

- an "Abus" quality padlock for its heavy duty chain locks

- dual locking feet on all of its mid-priced and high-priced U-locks

- cut resistent steel shackles of "New York" quality on all of its mid-priced and high-priced locks

Rumor has it that Kryptonite will soon be shipping a "mini" u-lock of New York lock quality. Now THAT would represent meaningful progress in bike security.