The OS is very easy to use

windows os is intuitive and fast and everything is large and don't have to spend time pecking small icons.

Windows 8 mobile is a far superior OS compared to the Android as far as ease of use

I much prefer this OS over the other two

Great screen size and the OS just gets better and better

The Lumia Icon is a very responsive phone with a great OS and good connectivity.

The OS feels fresh and modern

Rock solid OS

Android is a great OS, tons of apps and a ton of phone choices

and I've worked with so many different operating systems I've lost count but half a dozen Unix variants, 3-4 Linux Variants, every version of Windows since 1.0, and the Apple OS.