MR,
I will second Tx's comments ... and probably add 100 words of drivel that are technically incorrect ...
Having a longer torso (~20.5") and round chest (54"), the load lifters on the frame+6500 are much, much more effective for me than with the frame itself. I agree "lift" isn't probably the correct term. Maybe tension distributors???
I'm no engineer, but I liken it to a suspension bridge distributing weight ...
The load lifters placed at an upward angle (6500) better distributes the pressure on the shoulders (for me) to the entire arc of the straps around the shoulder circumference instead of a single pressure point with the lower load lifters of the frame by itself. ... this provides great stabilization and enables me to adjust even more weight to the belt.
