Oh, I don't know...
I have a Lumia 800 that I got given for free. It was a gift, and you don't look gift horses in the mouth. So, I stuck a new microsim in and gave it a whirl.
It's okay. It's got some cool embedded features like music search or the quite swish QR code scanner from the 'vision search'. I thought the live tiles would be irritating but for messaging and email, they're fairly cute.
I can understand why people find the keyboard irritating, as it quite small. However, being a woman with fairly small hands, I find it a ton easier than the Android keyboard. I got used to it immediately, instead of struggling with the one on my other half's Galaxy S2.
It's not worth the 'upgrade' to the 900, but it's a nice alternative to an older Android. If you can get it free on a cheap contract, it would be fine for a non-Android user. But what do I know? I'm interested in the Asus Padfone!