I think when it comes to power users coming from android such as myself, it us hard to leave all of the incredible things that android makes possible. Because developers are able to take advantage of so many great api's and features of android, there are many apps that simply cannot be replaced by any other app on both ios and WP.
Some of these apps/features include:
Floating apps- Video players, browser, calculators, note taking, etc,. These sort of apps are taking off with both devs and OEMs such as Samsung. When out and about and on a text convo, webpage or call, I could pull up my calculator, a note taking app or browser without leaving current task and still being able to look at info on main screen.
Widgets. Some are useless(same as some useless live tiles). But some are very useful. Widgets allowed me to stay on the home screen and glance at information. Yes live tiles do the same thing BUT with widgets on android you can also interact as if the app is open. I had a file browser, dialer, calendar, calculator widget which enabled me to do tasks such as manage files on my phone, creating calendar entries, taking notes etc.
Any power user coming from android can tell you this. I am no fan boy and currently happy with my Lumia and coping.