I have a hyper mobile tailbone, due to a connective tissue disorder. My specialist told me to buy one of these. I did, and it made such a huge difference for the better! I take it everywhere with me. I’ve used it at home, in my car, at doctors appointments, at a dental appointment, and everywhere else that I need to sit my hyper mobile bum on. I have not felt comfort or support on this level in decades. My hips are staying more aligned, and my lower back pain is almost non existent. I have joint instability, so I use the original. The extra firm would be too close to normal seats that can pop my joints out of alignment. My specialist recommended the original. I also recommend the leather like surface. It’s so easy to clean when going from place to place.