Re: Trust, indeed
In my case because I recognise that under the hood it's as solid as the rest, and on top, the GUI is the most productive of them all.
Proof, should it be required, is the looooong wait for another popular OS to allow window resizing from places other than the bottom corner, and an equally long wait for things to maximize properly. Small things, I know, but things you do over and over again and want to work properly.
My primary machine is my Air when on the move, but it's always a joy to get back to my Windows desktop. I can even search for stuff easily on it.