Does not matter where you set the number! Imagine sleeping on an inner tube. Hard is more air, soft is less air. The tube still holds your weight but the tube just creates a bubble. This is a big *** job. I added a 4" thick down lined top after the fact. Made it a bit more comfortable, but still certainly not worth sleeping on.
What ever you decide, DO NOT buy one, like I did, to save money with the no return policy. Even though I imagine their return policy is a fraud and a *** also. Save your money.
Review about: Personal Comfort Bed Bed.
Monetary Loss: $1800.