i have been paralyzed for 30 years and had a history of skin issues including two flap surgeries. I've been using a Ride Design since circa 2004 but the last one I got about 1 1/2 years ago is not working out. I've worked with the company and other therapists, and ATPs to try to fix but continue to have pressure sores. Recently I found out about the Signature cushion made by Precision. has anyone used this type of cushion? I'm trying to get some feedback from users.