The R4 are way better then R1 in winter plowing. i have 2 tractors one with R4 and one with R1 and R4 wins hands down. Also the one with R1's now used to have R4 and I traded and I lost a-lot of traction in winter. have to put chains on it. the R4 have more rubber on the ground hence better traction in my opinion. i guess it depends on sticky snow versus powder versus tar or dirt surface but My R4 have never filled up with snow or mud it must be really muddy to fill treads. Maybe just type of mud(clay) or whatever. I would go with R4 hands down in my opinion. Strictly grass go with Turf. for field work (plowing dragging seeding haying) go with R1 but a combination of things from mowing to dirt work go with R4. Oh yeah I mow my lawn with the R4 and it dont mark it up at all but you cant touch lawn with R1 it will mark it up bad.
Mike
Mike