When we had ours on our previous motor home, it all depended upon where we were going. If we were going to travel where we would be making large difference in altitudes, we would just deflate the bags to about half. I'm not really sure if it would have made any difference if we had not, but due to the cost of replacing the mattress, we just never took the chance.
All it takes is a couple of minutes to deflate and re inflate.
Our new motor home came with a 10" foam mattress and we like it even better than the SN....so much so we replaced our SN at home with a foam.
Ron