Indeed, my GQ had airbags fitted by original owner.
Earlier this year I put new OME springs and shockers through car and also kept the air bags. Only needed 20psi when fully loaded and van on back before suspension upgrade.
Subsequently sold van and now have Tvan, but keep 5psi in bags when car empty, put around 10psi 'ish when loaded for trip plus Tvan.
Obviously can't compare new suspension without airbags, but everything travels very well.