In the last 6 months I've owned and iPhone4, Lumia 920, and currently a Note 2. So I've had my hands on most of the major player's OS wise.
iOS is the most reliable and adopted.
WP8 is cute, but woefully behind in function and features.
Jellybean based devices are the most functional at the cost of battery life, stupid quirks, lockups, complexity.
I love the size of my GN2, the hardware and options (SD card, removable battery, ect) and under appreciated things like customizable keyboards, functional download capability, and the ability to drag and drop music, video, and movies to it.
But good grief does it have some stupid ass quirks that drive me batty. The damn thing doesn't even have lock screen controls for most basic music functions, Slacker music is an abortion trying to use over blue tooth, it's got a terrible battery drain that is compensated by a monstrous battery size, and just odd little things like screen response, the screen not turning off after inactivity, and other little nagging things just make me wish for a larger sized iPhone again.