Ok I am now officialy sold on Air Bags over Timbren jounce bummbers ( bump stop). I have a 2003 Dodge 1/2 ton 4X4, Hawk shell. For the first 2 years I used Timbrens and thought were great, very little sag, everything felt good. Girlfriend bought me some Air Lift air bags, WOW what a diference I am only running 15 lbs. in each bag. Its a compleatly different ride every aspect of the suspention system works better smoother, less body roll. Almost a new truck feel. I am leaving on a trip this weekend for about a week and will report back the offroad change.