Not 4wd(tractor ha ha!!) but have this on me 2wd sapphy, 300lb 9" front 200lb 12" rear, but imo rear is a tad too soft, will be trying some 225 or 250lb rear, when engine rebuild done.
It's defo firm, but VERY controlled and I like it, no one really finds it uncomfortable, esp in rear.
tabetha