Ah, makes sense. I think that the newer rides have lower height requirements because wherever possible the vehicle and restraint system are designed to accommodate more rides. But height restrictions aside, many non-riders have a trigger. I have one friend who has no problem with inversions but won't do TOT and another who is fine with TOT but is terrified of any inversion.
I'd describe Space as a spiral. It's like a mini-coaster on top, and then it basically settles into a spiral. Compared to BTMRR and Matternhorn, it's a relatively smooth ride. I'm not sure if it's like this for new riders, but if you look ahead, you can mostly see the track. I think HSM and SMGG sort of distract you from the ride motion, but if you ignore the screens, it's a pretty straight forward ride. Unless your trigger happens to be the dark.