It will be by primary mower and snow pusher.Turf are better in grass and snow but load up and don't clean out as well on dirt and mud.
R4s are fine in snow if you have weight on the back for traction but they are not as good as turfs in the snow.
I push a lot of snow with my R4s with no problem but I have 500 pounds of ballast on the three point.
If you're going to be working in dirt a lot I'd get the R4s.
If this is your primary mower and snow Pusher I would get turfs.
I have a GC 2400 similar size as the one you're looking at. I do not mow with it.