Yikes!!! I know these things are supposed to be a bundle of energy etc etc but, man do they taste bad! The first time I tried one I thought it had gone off or something.
It might be a matter of preference of course and there are many flavours to choose from, but I'd be hesitant to try one again.
Edit (29/11/04) Well, I didn't have the courage to try another one, so when a friend bought one I didn't talk him out of it. Instead I waited for his reaction. It was the same as mine! I know, using your friends as guinea pigs isn't cool but I wanted an unbiased opinion!