Really want to love them, but bought them and used for over 2 years around 1997. Can't say i like them. The reason i don't like them is because, i often hop around chair with different positions, sometimes sitting with chest on back rest, sometimes squat on chair, sometimes lotus position. But with the kneeling chair, your legs are fixed. Your upper body, is like a joystick, a tree swaying in the wind. You can't readily get off since your legs are weight tied. You have to do a dismount.
If you have a question, put $5 at patreon and message me.