Living with no key is great. Just need to remember a 4-8 digit pin code. All I carry now is a key fob for my car. I live with my girlfriend and we each now have our own pin codes on the Yale lock, super easy to use and I've had installed now for 1 year and have not had to change the batteries yet. The auto locking feature is also nice so no one forgets to lock the door, it just locks after about a minute. If I'm expecting friends or a maid I can input a new code for them in 2 seconds right from the lock.

My ideal lock is pretty close to the Yale: - Physically tough (not sure if the Yale lock is but it feels pretty hefty to me) - No key hole - 4+ digit pin codes - Multiple pin codes - Auto lock only when door is closed (the Yale does it based solely on time) - Easy way to plug/unplug a z-wave or zigbee module. Although I don't see much benefit to having my lock hooked up to the internet. I can simply tell people my guest code that is programmed on the lock if I need to let someone in and I'd prefer not to open up another possible attack vector.

I also have a Samsung EZON 3120 which has been discontinued but I like that it locks only when the door is closed.Also when typing in a pin code it makes you hit two random numbers on the key pad before entering your pin code to make it harder for someone looking over your shoulder to figure out the code and/or leave fingerprints of your code on the touch pad.