When comparing to others settings, don't forget to add in weight of riding gear. My typical cool/cold-wx (boots, pants, jacket, helmet, and gloves) tallies a bit over 20 pounds (9 kg). I used to weigh about 220-225, but am now at 185-190 (w/o gear). I haven't weighed it, but I bet wife's cool/cold gear totals over 15 lbs. My gear drops to about 14 for normal warm wx riding - summer boots, mesh pants, mesh jacket, lighter-weight gloves. It could be significant.
I think there is a post or link to a resource on here somewhere (I don't have time to hunt it right now) that gives a step-by-step guide on setting the preload and damping. You need 2 or 3 people to do it properly though.
After I refilled the preload adjuster (resistance at 3-4 clicks) I find that I like about 1 turn past the "standard" setting (I believe is seven turns total?) is good for daily solo riding (for my preference). I think I have added 5 turns for casual 2-up riding, and maybe 3 more for loaded-up trip riding. I haven't found a need to change the preload - it is set for "release from as much compression I can give the rear, and look for just a tiny ?-cycle oscillation at the top, then add ?-? turn.
For normal riding, I run 40 psi frt & rr in PR3s. I go to 42 psi frt&rr for 2-up, or doing something like precision riding stuff/low speed maneuvering practice/rodeos for a little lighter low speed steering. I also add 2 turns to the preload to stiffen the rear and give me a touch extra ground clearance for the tight turns.