It was amazing, but I will never get on it again.
I rode in July '04 and the only thing keeping me from losing my lunch was the fresh air they pump at your face. I just don't think it set a good tone when there were barf bags on an amusment ride. The acceleration was so strong that the water ran out of my eyes into my hair. I mean, it was really really cool, but it took us an hour of sitting in a quiet part of Epcot with water and food to feel okay again.
I have heard of lots of people who think it is great. I've read things that say they've turned down the acceleration to about 2.5G's instead of the original 4G's (I don't know if that was before or after I rode it). I am still glad I went, but between waiting in line, pleading with myself to not puke all over myself while riding it, and the hour it took to recover, I won't be going back!
I'd say if you really want to try it, don't let me stop you, but schedule in some "recovery time" for right after!