I am curious also. I bitched about Skidoo suspension/shocks for years, bought aftermarket. Until the Expert. They got it really close. Like better or same as Freeride. But regardless of SP/X/Expert: Full stiff on ski shocks, around 4 on torsions, I leave the center alone.
Same spring rate different valving.
I love the next step stiffer in the spring chart (not the big boy one they recommend) you have to look at the actual spring rate.