Good advice, Larry
I remember driving my Suburban at the ATHS show in Balt/MD and at the ATCA show in Macungie/PA with 6 big-boy passengers. The 1,500+ human-weight load was noticeable on corners, and when braking. In PA, it was nice have the SM420 sub-low gear.
Previous to those events, the last time I had a full load of people (hippies) was on a 500 mile trip down to Atlanta Georgia to see the Grateful Dead in 1973. I do not remember much about that trip, or even how well the truck drove.
Softer springs have never been in my mind or in my plans.
"If it will just be a cruiser and won't be called upon to carry a full load of people and stuff, I'm sure you can find some softer springs." (Larry)