Just picked one up today. Have paired it with a Galaxy S4 on Android 4.4.2. After only a few hours my initial impressions are great. Have used many devices in the past (Gear 1, Sony Smartwatch, Qualcomm Toq, LG G Watch, Fitbit, Polar Loop, Garmin Vivosmart). Like the design, screen is vivid and responsive, social and messaging notifications work great, heart rate monitor seems accurate. I will try it on a run tomorrow and test out the GPS and Heart monitor. The MS Band seems to blend activity tracking and basic smartwatch functions very well right out of the box. My guess is it will get even better with public use and feedback. Thanks MS!