I got a WP7 phone (the HTC HD7) after realizing that I had a top-of-the-line Android phone (the HTC Evo) and, even with CyanogenMod, it still felt really slow. Almost worse than an iPhone 3G. For me, WP7 feels a lot better than Android or iOS.
Like you and the linked article, I really enjoy working with the WP7 development stack. I'm currently working (with 3 other devs) on a mobile application for 4 platforms (iOS, Android, WP7, and JQuery Mobile).
Even having skipped an entire sprint (~10 days) to focus more on Android, the WP7 app is progressing along further and faster than the other clients. Just having support for (albeit limited) databinding is a huge win. Plus, you get great looking apps pretty much for free with the theming defaults.
That said, I have access to a few Windows phones (HTC Surround, HTC HD7, and some keyboard phone) and I would not be able to switch to any of them over my Nexus One. Dealbreakers for me:
* The search button is locked to Bing (not configurable)
* The browser is not only IE, but a crappy offshoot of an old version of IE (I believe IE7 w/ a few patches)
Can you please post your per-platform usage stats after you launch? I think that it would be of value for the mobile developers here.
Also, since you are attacking simultaneously on four fronts - a blog post about the advantages and disadvantages of developing code and assets (graphics) for each platform would be great (obvious one - no IB/ExprStudio for Android?).
Have you tried CM7? One hour after installing the CM7 release candidate, I found I was in love with Android. It's like upgrading from a cheapass Windows XP netbook to a MacBook Pro with an SSD.
Also, I may be completely overstating how slow it was. It definitely wasn't unusable, but it felt slower than it should have been. This was after multiple wipes to multiple ROMs too.
Consider how much data you're putting on it. No phone is going to be fast when you ask it to pull down 5gb of email as some of my users do. The iPhone isn't that magical.
