I installed air tabs on my Holiday Rambler 33' Vacationer and became a believer. The biggest improvement I noticed was fast passing semi's did not cause the coach to sway as before. That doesn't mean some semi's still cause swaying but it eliminated the major of the problems. I believe fuel consumption may have improved. I normally pulled a vehicle but the one time I did a round trip to Ca. with out the car, fuel consumption was the best I ever experienced with or without an auto behind.
Once you get out of Arkansas I 40 to Seiverville is a great road. Quicker than going through Chattanooga. I live in Kodak, Seiverville exit 407 and travel to Az. yearly. I just came back from AZ in Jan. and I 40 is still a good road (even the truckers rate it highly) I recommend T. Sawyer RV park in Memphis and a trip to Beale street for ribs.