I run Linux on my home computers (for the last 7 years). I am required to use Windows at work. My work laptop, running XP died last month, and was replaced by a new one with Win7. While I will grant that 7 is better than XP, I am still thankful that my actual job requires me to SSH into Linux servers all day. I even prefer the Linux command line interface to using Windows.
My son bought a 2nd-hand Mac yesterday because he was tired of dealing with Windows with his assorted iDevices (

). I had to help him set it up. It made me glad I don't have to use it regularly, either. It's certainly not "intuitive", and I don't care for the looks.
As for UIs, I don't care for gnome -- never have. I like KDE, and I also use enlightenment and xfce regularly. Lxde is also good on "resource challenged" systems.