Not a Zacspin but similar: Green Lantern at Magic Mountain in its opening year spun with a force and speed that was hard to believe. I mean, literally. When I was waiting in line, multiple groups kept looking up at it going and leaving. I found myself walking forward very quickly through the line (when does that happen? Not one group but many?). Then as for the actual ride, I could handle the insane spins, but the way that it flung me head first over the cliffs of the ride was kind of mentally/physically overwhelming, as if it were not something the brain was meant to handle. Soon afterward, the park modified the ride to make it spin less, and the main complaint from people shifted to the feeling of being banged up in awkward parts of the body.