I have no motion sickness problems but I can tell you one thing, Star Tours jerks you much more in the back seats than in the front , still with that , it's not that bad. Body Wars though is different, that one really jerks you around big time.
I don't have a problem going on anything , simulators, roller coasters, but ....wanna get a good laugh? Don't put me on the balloon race rides going backwards....I reaaaally get dizzy there! Go figure.