It depends on what kind of rollback it is. I wouldn't wanna do it on a lift hill, but as long as it's a LIM launch where it's anticipated and safety precautions are in place, I'm sure I'd enjoy the surprise.
Now Elfman, which Mr. Freeze did you valley on, and whereabouts on the track? Didn't make it all the way over the tophat in reverse? I always wonder if the train is gonna valley on that part, because it always barely makes it over the top when it goes through in reverse.
And how do they get you off the ride when it valleys anyway? I know they have valley floors and stuff wherever they expect it, but the trains don't always valley where they expect them to. Do they have a special device for that? BTW, I sure would like to know how one of those tow cars works. I know they use them for testing and stuff also, but I don't quite understand how it grips the track and has enough power to push or pull several tons of train while it tows!