Joel,
I have played with pressure. My problem is that the air moves to different pockets. The longer I sit , the more it gets flattened , pushing the air to the front under my legs. I am constantly adjusting how I sit. I have spoken to my OT, and she has left msgs with OMS (where I got my chair) and ALS Loan Cabinet in Toronto. She did so from my place on Thursday. I have Rehab on Monday , and will bring it up there also.
Glen