I went with Android. It feels a bit like Windows 7 on a phone. It's what Microsoft should have built, if they were on the ball. It's excellent. It's made me a Google fan, not just a user. That, after being a staunch Microsoft supporter for the past 25 years. I still have plenty of Microsoft in my life, and that won't change. I cannot see myself without a Windows based computer, but my phone will always be Android, and my favourite browser is certainly Chrome.
Being on Android doesn't mean you have to leave Microsoft behind, though. Onedrive, Outlook, Word, Excel, MSN Money, MSN Weather, Skype, they're all there on my phone. Microsoft has seen the writing on the wall, and they've been aggressively pumping out excellent Android apps. I have a bit of a split personality. I use many of Google's competing services as well. To be truthful, most of my life now flows through Google's world (by choice), but I maintain a parallel existence in the Microsoft world as well; Android lets me do that. That is possibly Android's greatest advantage: freedom. Google never tells you that you have to use their services (except, maybe to activate your phone!). You can decide what you want. There is a lot of choice too!
Google's world integrates very easily with Microsoft. On the desktop, you can use Google's apps through Chrome--most of them through any browser. If you don't want to use Google's apps, Microsoft's apps integrate very well into Android. It's a great fit, no matter how you look at it.