I've been using a Windows phone for about four months now and I have to admit that while it was the cheapest smart phone upgrade path, I really like the layout and design of this OS. It is intuitive, the look is great and the functionality very useful. If I were to go to a tablet, it will run Windows 8 because all of my software is Windows compatible and the Microsoft Tablet is the only one that will run a real computer OS, not some strip down version for mass consumption. The fact that my phone has fully functional versions of Excel, Word, Powerpoint and some other applications makes it the first time I can travel without a laptop for some business trips.
That is simply my opinion. I know Apple and Google control most of the market now.