Hi Tankie, let me confess upfront I am not a techie, so take all my comments with a grain of salt.
Searching for a softer, less bouncy ride combined with 6K axles with 3 leaf springs that broke last summer, I made several suspension improvements including being upgraded to the 7K axles that included new brakes and 6 spring leaf set. This upgrade causes a rougher ride on the truck and inside the rig, as its a stiffer suspension, as many owners can attest. The Lippert West Coast technician replaced the axles and installed the Centerpoint Suspension, which replaces the equaflex, and adds two horizontal air bags, one on each side between the axles, with airbag gauge recommended to be set at 70 lbs. PSI. This also removes and replaces the useless semi-horizontal factory shocks that everyone complains about on this forum. My suggestion would be to read the available Centerpoint Manual at
www.trailair.com, which would truly explain the purpose of this semi-air suspension and its benefits. FYI, Trail Air is now owned by Lippert. I can only tell you, since we made several other improvements to the suspension, my DW and I both noticed reduced bounciness, better control and side to side smoothness in ride and in turns due to the Centerpoint. When finished driving for the day, we noticed the inside of the rig looked exactly like it did when we had 6K axles, with nothing major out of place, including zero open cabinets and no dishes on the floor. All in all I would recommend Centerpoint Suspension for those who cannot afford the IS and disc brakes etc. expensive upgrade. You could call this the poor man suspension improvements. We made a few very choice other improvements including adding an air bag hitch, that I would have to say has heavily contributed to the smoother ride. Let me state clearly, the Centerpoint Suspension is just one step in softening your ride, but for the price Lippert is charging I think it was worth it. Don't forget you are driving a bucking truck, and a heavy rig, so a pothole or a poorly paved street will still shock you and roll your eyes a little, but at least it's not like demolition derby time any more.