I use an Android phone, and have played with iPhone. My coworker has a WP7 and is quite the WP7 evangelist (well former co-worker, he left recently). I do not see any hug difference in them worthy of the fighting hatred that each camp has for the others.
With the death of WebOS I really hope MS WP7 can take off, else we will be faced with a Android majority share, and iOS taking the lion share of the remainder... which is NOT good for consumers. The problem is MS WP7 not only has tiny share so far, it lost ground over the last quarter. I do not know what they need to do to change public opinion, but right not the general feeling of the market (valid or not) is that WP7 sucks.