I like the gradual power increase that you get with a twist dial, but it's often hard to handle one of those with only one hand. For that reason, I prefer up/down buttons.
I usually really dislike twist controls. They seem so clumsy. But the button position matters more than anything. I love my Gigi, but it's so frustrating sometimes when I'm in a good rhythm and then I'm jolted out of it by accidently hitting a button.
