Harry Potter Forbidden Journey was AWFUL for me. I was soooo OFF for a good 45 min afterwards and I am normally not a "motion-sickness person". But.... I did go on again with my family 2 years later (call me crazy!) and this time I was prepared to close my eyes about 1/2 or more of the time and then I was fine when I got off.
I do not have problems with car/bus rides or rollercoasters in general. Sometimes 3d movies will affect me in that it may set off some migraine symptoms. Usually the 3d stuff at disney is so short (20 min or less) it is not a big deal so I can manage. I never opt for 3D option in theaters at home-- 2 hours is too much. I am usually fine with Philharmonic, Bugs Life, Muppets, and others.
All that being said, when I feel like Star Tours is too much, I remove the glasses and/or shut my eyes for a few moments and I feel better. I am always okay within a few minutes off Star Tours. Occasionally, when my family wants to ride a third (or more) time on Star Tours in one trip, I may sit out.
The jerky-ness (and it is there in FL's Star Tours) doesn't affect me/bother me as much as the visual aspect. I find when I am affected, looking away, closing eyes is the easy fix. However---I have heard that on Mission Space, you should NOT close your eyes this will not help and may make symptoms worse. I have not and likely will NOT brave Mission Space! Not worth it to me to be sick/nauseous/ affected for part of my day!