My realizations about the WP OS after going to Android and coming back...
After being a long time user of a WP7.5 device, I switched over to the HTC One back in May of this year. I recently came back to the Windows phone family and have realized some things.
First thing I realized was I had my head in the sand regarding some of the complaints/criticisms people have made over the months regarding the Windows Phone OS. I was always a big proponent of WP so switching over to android was done very begrudgingly. (I ended up going to android b/c I was switching my service to t-mobile and t-mobile was not offering any compelling WP8 devices when i made the switch).
2nd realization: After coming from a world of live tiles, i never understood why people were so caught up in having a notification center in WP. After using android for 6-7mos and switching back to WP, i now realize why ppl love notification centers so much (despite having livetiles). I am constantly trying to swipe down on my Lumia to access the notification center but am quickly disappointed b/c WP does not have one yet. I'm looking forward to getting it back with the WP8.1 release.
3rd realization: Apps do matter. As much as I still love the way things flows in WP, apps are very important for the health of a mobile OS (duh). After being able to access pretty much any app I wanted in android, it's a little disappointing not to be able to do the same using a windows phone.
In a nutshell, if WP is a users first foray into the smartphone universe, I think they would love it and have no issues with it. BUT....I realized it's much, much harder for a previous android/iOS user to switch to WP and love it b/c there are so many limitations with the OS. The app gap has slowly been closing but still has a long way to go for WP. I never thought I'd say this but i actually missing using the HTC One.