We rode MS in late June of last year (during technical rehersals) and suffered no ill effects. Even my 71yo MIL loved the ride. She's looking forward to our trip in June/July 2004 so that she can ride it again. My DD Sarah who suffers from motion sickness on long car rides also is looking forward to another trip to Mars.
I think that the media and internet have instilled a lot of FUD about this ride. (FUD = Fear, Uncertainly, Doubt)
If you tell enough people that they WILL get sick and that the ride WILL ruin the rest of their day, it will end up having that effect. I liken it to a trip to the dentist. I've experienced pain in the dentist's chair, so I anticipate that every trip there will result in my feeling that same pain. Even if all I'm doing is going in to have my teeth cleaned. I get so worked up that the slightest discomfort makes me go pallid white with fear. I think that the same thing is happening to people who haven't tried Mission Space. They are so conviced that the ride will make them sick that they work themselves into a panic.
You have two choices. Ride it. Or don't. But for the sake of those who haven't yet experienced the ride, please don't comment on the actual ride until you've tried it yourself.