I have work dual rate fronts set up for my weight and plan on doing the same to the rear. However the lake is frozen and my tires are studded and ready to go. Won't be doing much rough riding anyway since the lake is pretty flat, I kinda wanna just get out there. I'll try it with the z400 shock and spring, then swap the 250 spring on and see which is more comfortable for now. 

I use my quad for long tours on the lake in the winter, then xc and mx in the summer.