Cells collapse if you shift position
Have owned and used this for a couple of months now.  I'm about 225 lbs and not sure if that is too much for this cushion but it is not very comfortable.  You have to sit straight down on it and not move for it to work.  If you shift position at all the cells seem to collapse and suddenly you are sitting on a hard surface again.  I've been placing it forward on my chair to allow spinal relief because it becomes too uncomfortable once the cells collapse.  Don't believe the hype - this cushion is one of those products that performs great under very specific test conditions but fails otherwise.
Rating: 2 stars