I've had tush cushes for years on nearly every office chair but it doesn't really make a difference for me. I have to have something very firm to sit on and not sit long because that segment of my low back (the lumbar segment that is) can't seem to support itself and just craps out under sitting. My tailbone even with a tush cush cannot take sitting for long and the worse seems to be in an airplane. Sitting while driving is killer too after about a half hour. Sitting at someone's home is really a pain esp. if the cushions are soft, I'm DEAD!!!!!!!
I think my disc spaces are just narrow to nothing when I sit but give me a transforaminal ESI and I'm good to go~ feels so nice with the irritated spinal nerves bathed in the steroidal goo