I've gone on it several times. It can be intimidating - waiting in line you get up higher and higher (great view over WDW!). And you realize you are going to have to get DOWN from that height! Several times it was all guys in the line and I was the only female (not a young one at that).
There is a CM controlling each person at the top. It is NEVER unattended. When it's your turn you sit in a little 'pool' area of water and there is a bar in front of you. The CM instructs you to cross your feet and cross your arms across your chest. They will not let you go down with water shoes on - the could/would catch on the slide and that would NOT be a good thing. The CM waits for the person before you to get off at the bottom before he allows you to go. You kind of have to scootch yourself forward to get your body over the 'hump' and start down.
It's a bit unnerving to be sitting in the 'pool' waiting to go over and you can't see the portion of the slide near the top - it really feels like you are dropping off the edge of the earth. (A leap of faith.)
I love coasters, thrill rides, speed and am not afraid of heights but this can be intimidating.
I felt that after all that anticipation, it was over way too soon. You are traveling so fast (officially it can get up to 65mph) that I felt I couldn't enjoy it. I had to keep my eyes closed because the force of the water spray stung my eyes - it hurt and I couldn't see. Picture hanging your head out the car window in a strong rainstorm going down the freeway at 65mph with the rain driving into your eyes.
The other thing that can affect someone psychologically is that (even though it is engineering properly) you are not "contained" or secured in like you usually are in thrill rides. I always wonder if someday (God forbid) someone might go off the edge of that slide.
Also, besides the one piece swimsuit for ladies, the other suggestion is to be sure to tighten your rear end muscles or you will have water driven up where you don't want it - alot of people go running for the restrooms after that waterslide!
Despite all the above, I have subjected myself to it several times. I think for me it's mustering up the courage and proving to myself I can do it that drives me.
I hope I didn't scare the heck out of anyone but knowing in advance might help you decide if it's for you. You can always walk up and chicken out - I've seen people get up there and they just can't do it. I doubt anyone would be unkind about it.
Rhonna