Yes, the air pressure in the bladders changes with elevation. Normally if our elevation changes over 6-800 feet between stops, we adjust the pressure.
The design of the system doesn't allow bleeder relief valves, so a person has to be wary when traveling in mountainous territory. As mentioned above, it is very easy to get in the routine of lowering pressure as part of the pack up process, and resetting pressure after setup.
My wife and I prefer different firmness levels. We had our Sleep Number for about 6 years before we went full-time, and moved it into the trailer. When the rig was in the shop and we were staying with my daughter, we took it to her house.
One of the very best purchases I ever made.