The Basis Band is by far the best sleep monitor I've ever seen on a fitness tracker. (That's excepting gadgets like the Zeo, a brainwave scanner which can detect phases of sleep. But it requires strapping a headband to your skull, which is just the kind of "new unnatural life-habit" Basis is trying to avoid.) The Fitbit One has a "sleep tracker," but lord, is it awful. The Fitbit requires you to take the gadget out of your pants, put it in a wristband, press and hold a button right before you fall asleep (how is this even possible?), and then press it again as soon as you wake up. I managed this pain-in-the-ass exercise maybe twice in two weeks. But the Basis Band requires no extra work. It uses its optical blood flow sensor in concert with its accelerometer to measure your sleep--if you're stationary and your resting heart rate dips, you're asleep. The use of both those sensors allows it to figure out if your sleep was interrupted, even if you didn't get up from bed. And the web app gives your sleep a very simple rating, showing how long, how many times it was interrupted, your resting heart rate, and then your "quality" of sleep. Last night I scored a 94. Not sure if that was out of 100 or 1,000, but it was a good night's sleep.