Millennium Force, Maverick, and Dragster are all glass. The B&M's are aging a bit but they are still pretty smooth, although Mantis has some strong positives in the second half that are hard on the legs. Magnum gets a rap for being jerky on the trip back, but personally I love it. Really the only "rough" rides are Mean Streak and Blue Streak in the back of the train.
Islands of Adventure blew me away with smooth as glass rides, but its not that hard when the only coasters are B&M's that are well taken care of.