I do feel Alton are ready for a very high tech dark ride just like you get in Orlando, but I wouldn't want it to replace Duel or the 4D cinema as those attractions work very well. CACF is one ride which does need replacing completely.
Also if you look on an aerial map of the Towers, behind Towers Street and CBEEBIES, there is a staff car park. Plus most of the shops on that side of Towers street are empty, you only have the pub, Box Office and Guest services on that side leaving room to use those shops for the entrance to a dark ride. Then the car park area at the back could be used for a large ride, it could be CBEEBIES themed or any theme to be honest, but if you have a transit system like Duel, Tomb Blaster etc in there, then you can take guests round on an adventure, it would not take up any green space, it would re-vitalise Towers Street drawing more people to the area too.