After testing an HTC (work) and Lumia 900 (off-work) this week, I'm personally sticking with the 900. It had nothing to do with battery life (HTC was about an hour better under the same workday as the Lumia was, at around 22 hours vs 21, which to me is about the same), call quality or ability to get/hold a signal (again, about the same), or availability of apps (I do miss a few apps that WP doesn't have, but this is primarily a work and PIM device (hence my testing of the HTC at "work" functions, as that's what I'd primarily do with it), and I don't game or use apps much other than newsreaders). What really got me is the UI - Sense is really nice (reminded me of my HTC WinMo 5.x / 6.x days!), but it just seemed like such a mess underneath. I've gotten used to having everything in a few areas on my Windows Phone device, and I really can't go back (no matter how much customization the droid had).
I think that's what made it for me - I realized I really wasn't missing anything I needed on my WP device, and it does what I need in the way I like to work. To each his or her own, and for me and my work/lifestyle, the WP ecosystem works better, that's all.