I'm pretty sure the whole experience is the same from when it opened, although I have heard the twister may have been bigger and a lot cooler to watch. Twister is an older attraction and some effects don't work as great as they used too. But for running 365 days a year I don't really mind the occasional mishap.
Also, does anyone know why they started using water insted of ice chips as broken glass about half way through the show? Saftey? I heard about this in a video of a V.I.P. backstage tour.
I also forgot to mention that the movie theatre sign that flys away was not working. Not sure if its been fixed or not.
I think water would probably be easier to use than ice chips. I agree ice chips would be way cooler in simulating broken glass though.