OK, so went over to the MS Store at lunch to take a look w/ interest in buying. I came away empty handed by choice.
The big problem for me is my small wrists. Unlike the Apple Watch which comes in two face sizes, the MS Watch is one face size w/ multiple size bands. With the display straight, not curved to naturally conform to the wrist, I found it awkward and uncomfortable, and also dorky looking. Maybe this is why so many of the official pix show people wearing it upside down.
As far as the watch goes it's a nice piece of tech. The OS is smooth, responsive, and intuitive. I had no issues figuring it out myself. The screen is very bright and seems to be non-glare. It should be readable in sun light as advertised. One problem I have w/ the screen though (and this might be the case w/ the Apple Watch too) is that when its off it looks stupid -- like you are wearing a turned-off computer. Take something like the Fitbit Force, which, of course is a different kind of screen, that blends into the band when off. Much cleaner, less nerdy, appearance.
Since I didn't get to workout w/ it I can't say how accurate it is. The heart rate monitor was no better than any of the iPhone apps, that is to say not great. My typical resting heart rate is in the high 50s to low 60s (as measured by a chest strap monitor). The MS band had me in the high 60s up to the low 80s. So that was another reason for me not to get it.
Bottom line here is I think the watch might appeal to male tech geeks. It won't appeal to anyone else. MS missed again mostly because of the (go figure) aesthetic design.
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On the MS site's description it says "24 hour" heart rate monitoring, which I fear means that it is not a real-time heart rate monitor.
It's not. MS even state's its an "estimate," in its literature and on the web site. When wearing the watch it polls your heart rate as specific intervals and then averages it out. When you go to the HR screen you can see if it's "acquiring" or "locked" onto HR. The main screen will show the most current HR.