I'm going through the same thing at the moment. My rear wheel has a valuable internal hub and my front wheel has a dynamo. I asked my bike mechanic and he said he can get the Pinheads and Pitlocks off without the key. Customers leave their bike in the shop and forget to leave the key or they've lost it. In the end, I decided to secure my front wheel with and Abus Nutfix (arriving today). I decided I just can't feel that secure in Portland without a u-lock around the rack and through the rear tire and frame, so I've got an Abus Granite 540 on order. It's lighter than the equivalent sized Kryptonite. I'll probably still use a cable looped through the front wheel anyway.