I would love to hand piece because it becomes a totally portable project. Jinny Beyer had a video out that demonstrated her method, which is *extremely* fast. Basically, instead of moving the needle in and out of the fabric, she moves the fabric onto the needle. I borrowed it from the library years ago; don't know if it's still available.
Unfortunately, the fingers on my hands are quite odd lengths and the muscles in my hand cramp up really fast when I try to hand piece. Most people wouldn't have this problem, I think.