I have a BodyMedia Armband, the middle one, not the cheapest one. I love it! It tells you how much sleep you got, and the quality of that sleep, how many steps you take, how many calories you burn, and the software is easily downloaded and synced with your band. I think that after 3 months you have to pay a subscription fee to get your information, but I'm not 100% sure of that. I don't know about the other two.