I've been meaning to learn the Dvorak layout, too. I'm concerned that it might be too confusing to have to switch back to QWERTY when using other people's computers, but perhaps that's something you get used to.
He has always had trouble switching back and forth. All of our computers at home were set up to be switchable. The main advantage I see with Dvorak is that you're less likely to get tired hands as you don't move around as much. But speed-wise, I've read that both layouts accomplish similar speeds.