The new models are Iseki, with Iseki engine and transmission, will need to do periodic Regen procedures. I thought I read somewhere it was tier 5 now. Hood looks better in my opinion, but that's just cosmetic. Wish the hydro pedals were in the floor vs being suspended from the center console. They just feel weird to me.
I have the R4 on my John Deere but I might want to try out the newer combo tires, they are kinda a cross between turf, ag, and snow tires I think. People say they have decent traction. R4 suck in the snow.