I totally agree tohot2se, It all depends on the design of the coaster. Raptor screws me up everytime I ride, yet I rode Dueling Dragons at IOA 4 times in a row in 20 minutes and was not dizzy at all after it. These are the same types of coasters but they apply forces to your body in different ways. IMHO Raptor is extremely high in the Lateral G area, constantly throwing you back and forth through tight turns, loops and swings. This is what makes me sick. The Millennium force has extremely low lateral G's because all the turns are banked perfectly. For other people it may the the vertical G's that make them sick, MF swings back and forth between positive and negative vertical G's quite a bit and it is certainly understandable that this effect may make some people sick. As all people are different, every ride will affect each rider differently. But you won't know how it affects you until you ride it. Soopahman, it is admirable that you want to warn people about the possible ill effects of the ride, but each person should already have some idea of how it will affect them before they ever get on. I highly doubt that a ride this extreme will ever be someones first rollercoaster. I believe that making a decision to ride or not to ride based on someone else's reaction to the ride is not in my best interest. Each person has to evaluate the ride on their own and it is hard to evaluate it without riding it.
CWD