i came from Android after nearly 2 years with a Moto Milestone (Droid in US).
I loved Android, the way you can customise it and change everything etc, but after having a custom rom of Gingerbread. It was slow, forced closes, random reboots etc and it done these before the custom rom.
The most annoying thing? The way Android seems to be just a random mix of apps. It's like they just got a bowl and throw all the things in and crushed it together.
Why the heck is their a separate gmail app from an email app? Everything just seems to be apps and not integrated into the OS, every app looks completely different to the OS and it just seems so inconsistent.
Thats why I looked at webOS but then HP announced they are dropping hardware and I jumped ship to WP7.
The best thing i have ever done, so smooth and fluid, looks very integrated and most apps seems part of the OS as in they look similar and carry the same theme.