Fwiw I set my mom up on 11.10 a few months ago. She was coming from OSX and immediately took to and came to love Ubuntu.

I think part of it is that with Unity, there are never overwhelming amounts of options on the screen. Once you understand that Super Key = Search for Application, that's pretty much all you need to know.

In the past, I think the "Start Menu" style application-chooser would have been overwhelming for her - I know it was sometimes for me. I'd click then start reading through the menus "Uhh, wait, what did I want? Where is that again?"

Even with the occasional Unity glitch (which doesn't seem to be an issue at all in 12.04) her system is still much more reliable than ever.

I was really impressed and excited to see that Linux was at the point where she could use it with very little coaching - so, worth considering that much at least.