Schwarzkopf shuttle loops are absolutely wonderful rides. Greezed Lightning at SFKK is Six Flags Great America's former Tidal Wave. That was the ride that got me interested in coasters, way back in 1982! I have also been on Montezoomas Revenge at Knotts Berry Farm, and it was a hoot too. Back in 1996, I visited Paramount's Great America, and at that time they still had their Tidal Wave (ours was removed in 1991 to make way for Batman in 1992. Great rides, they are, and there should be more.