This was the feeling I had when I had played with the recent versions of WP. It felt like a fantastic OS, and the hardware ran it brilliantly.
My own personal showstopper isn't a fault with the OS, but with how the phones look. Nokia just seems so far behind in terms of designing an attractive phone.
If Nokia were to release a phone that looked as nice as my Galaxy Nexus, had a large screen, and didn't cost an absolute bomb I'd probably go for WP over Android.
I'll have to disagree with you on the design aspect. In my opinion Nokia N9 has been the nicest looking and feeling phone ever. When you have it in your hand the finishing feels great, especially the subtly curved screen that has deep enough blacks that blend into the black borders seamlessly.
Personally I loved the design of the phone most of all (plus how rugged it is). I got the iPhone 5C when I switched because I like the feel of the high quality plastic better. Unfortunately the iPhone isn't quite the same; it's slippery as hell and the colors are more pastel than the bold colors of the Nokia. In my mind the Lumia 920 was the best designed phone I've ever seen, but obviously that's just one man's opinion.
My own personal showstopper isn't a fault with the OS, but with how the phones look. Nokia just seems so far behind in terms of designing an attractive phone.
If Nokia were to release a phone that looked as nice as my Galaxy Nexus, had a large screen, and didn't cost an absolute bomb I'd probably go for WP over Android.