I haven't tried Lollipop yet - it's not officially available for my Moto G 4G yet. I go so few up with irritating niggles with Android 4.4.4 that I moved to Windows Phone. WP isn't perfect, but each day I use my L735, I grow to like the system a little bit more.
In my opinion, the only way to get a truly satisfactory experience with Android is to root the phone and install apps that require root access and to use the Xposed Framework to install modules that add basic functionality.
Without rooting I can't:
- install apps onto an SD card
- save photos to the SD card from a 3rd party camera app
- customise the Quick Settings
- remove many pre-installed apps
- set my phone to use 2G access
... to name just a few.
These aren't major issues, but it's GREAT on WP to be able to choose where to install most apps, photos, documents, maps, etc. And of course WP isn't perfect - notifications are poor, the Calendar live tile doesn't display my appointments for the week ahead (I need a 3rd party app), and there are only 4 toggles available on the quick settings bar (not sure if that is the correct name for it, sorry.)
If I were presented with two phones with identical specs, one WP one Android, at the moment WP would win for me. That might change when Lollipop is officially available; I don't know.
I think it fair to say that neither system is better than the other. They are merely different.