Last November I had to trade in my LG Windows Phone 7 phone. Unfortunately I was a month early for the new wave of Windows Phone 8 phones, so I ended up going the safe route and getting a Samsung Galaxy S3. To me there is one thing that sets Android based phones head-and-shoulders above the iPhone and Windows Phone competitors.
That advantage is replaceable on-screen keyboards.
I've used iPhone keyboards, Windows keyboards, stock Android keyboards and they all usually suck. They're awful. They guess the wrong words, "auto-correct" the wrong words, and generally do not make typing on the phone a happy experience.
But I after using the trial version I bought SwiftKey and haven't looked back since. Its made typing and working possible on my phone. Now I can't go back to Windows because of it!
I hope that in the future Microsoft will allow on-screen keyboard changes for both Windows 8 and Windows Phone. It would make all the difference for me. I'd love to be able to use a good keyboard with Word and Skydrive on my phone again!