I may be in a small minority here owning two Lumias, a Surface Pro 3 and a Band (1) but I'm really happy with them all. That's enough about me. Over the last 18 months I've completely trashed my Band as I clock up a lot of mountain and street miles through running and cycling. I've been waiting expectantly for Band 3 and have been getting ready for the let-down for a while - you don't get to be as big a Microsoft (and Nokia) fan as I am without being ready for the let-downs!
So, what will I do? Well, I want an activity logger that does everything that the Band does, as well as the swimming thing. I want the steps, the hearbeats, the notifications, etc, etc, etc. Band 3 already exists. It's called the Garmin VivoSmart HR+ and has been around for a few months. It even works on Windoes (most of the time). I'm buying one tomorrow. Microsoft were using Band to learn about wearables and IoT. As the article says, they (bizarrely) nailed it. Apart from the economics of being a Windows-based platform.
https://buy.garmin.com/en-GB/GB/wearables/wearables/vivosmart-hr-/prod548743.html