This feels like a classic case of just because we CAN do it doesn't mean we SHOULD do it:
https://currently.att.yahoo.com/news/worlds-fastest-roller-coaster-japan-044128122.html
It looks a bit like Kingda Ka and I won't be doing that one again. Once was plenty.
Space Mountain is like that for me. Once when I was riding it, I had my hands in the air and my finger grazed some track as we were whipping by. Had my hands clutched to my chest the rest of the ride and said that was enough.
I was on Space Mountain once when it malfunctioned. All the emergency flood lights came on so we could walk out. Seeing how tightly packed together that ride actually is will give you the willies.
Had that experience as well. Basically the generic "wild mouse" ride but inside. Probably won't be going on that one much any more. The herky-jerkey motion is a bit much for my back . Matterhorn is worse, as much as I like that ride. Will just be doing the "smooth" metal coasters going forward.