That's the one where I got into trouble of preorder delays, got the wrong size and finally returned it back. I just went to my local Best Buy store a bought one. Yeah, they messed up big time on their preorders. Sorry if this first paragraph is several months late already.
So, I've been using it for months now and I've been enjoying it. Although I plan to wear it all the time including sleeping, I just tend to wear it during my workout sessions and running. Sometimes it takes time for the GPS to get a lock but that doesn't bother me. The device was contenting to use as I also use it like an extension to my smartphone notifications. I put my phone to silent and no-vibrate and let all the notifications pass thru Microsoft Band.
Microsoft has been adding some new features recently that I've yet to check it out. OOOH I can now share my workouts complete with details like my heartrate/calorie burn graphs and my running path on the map. I'll keep on using it until it finally breaks, hopefully after two years or more.