I've had no issues. Wait. That's not true. I'm on the THIRD band in 10 months. The build quality of both band 1 and 2 was very, very poor. That said, I wish MS had stuck with it and continued to develop and refine it. When this band dies (and it will), that'll be the end of the journey. Kind of makes you wonder what they'll do with the health app.
Also makes me wonder what they're going to do with 2 years worth of my sleeping, gym going, calorie burning, step counting, GPs tracking data??