I know this is thread necromancy, but I think this topic is relevant (and continues to be until Microsoft and app developers make this question a lot easier to answer).
If marketing, sales, and even us passionate fans have to REACH to find features in WP8.1 that iOS and Android do not have, that's a problem.
I can think of only three features (not abstracts like "aura" or other BS) that WP8.1 has that iOS/Android does not have:
1) Live Tiles (that's the obvious one)
2) The People Hub with its social networking integration
3) A handset with a 41mp camera.
Am I missing anything? If this were three years ago, we could list stability, but this is 2014. Android is past the days of Samsung Galaxy S l models with Gingerbread and frequent lock-ups.
So UNLESS and UNTIL Microsoft provides a PLETHORA of killer AAA features that iOS and Android could never even dream of having, people are not going to abandon their Apple or Google ecosystems, re-purchase all their apps, and switch.