> Honestly the Microsoft Band being worn on the underside of the wrist was brilliant (I may be biased).

I think a lot of personal preference comes into this. I know some women who wear their (lighter) watches on the inside, I've never seen anyone with a bigger watch to this.

I just remember having a metal wristband that was just a little too loose and the watch body slipped to the inside of my wrist from time to time, and I hated that so much that I stopped wearing it until I got it shortened. It's not much but the weight distribution makes this horribly uncomfortable for me. Also it clanks against the desk while typing :P