As TripleR stated, I have an 8540 with industrial tires. The reason I chose industrial is for their weight rating (I do a lot of heavy loader work which exceeds the capacity of AGs) and their overall tuffness. I routinely work in a retired pasture that I am clearing out those nasty trees with thorns (locust I believe).
In any case, R4s were the right choice for me.
In 2wd, my 8540 doesn't hurt the lawn/yard much. Even in 4wd, if you don't turn too sharp it doesn't really damage things too bad. My area is mostly hard clay, so if you don't drive when it is wet you don't leave much of an indent. I am basically country living with a nice fertilized/treated yard. Not a yard I worry too much about, but I do take care of it. (I say this to try and paint you a picture of my situation.)
As far as R4s and your snowblower. I have an 800' gravel driveway that I clear once maybe twice a year from snow. I only clear it if it gets so deep my wife's awd Edge can't get through it. Since I don't have a blade or any other snow clearing device, I simply use my bucket curled all the way back an brute-force push the snow. This is not very elegant, however it works. (I also do minimum damage to the underlying gravel.) Towards the end of the drive, where it goes up a short steep hill, I have trouble getting up and have to move more snow out of the way. My point is, the R4s do OK in the snow, but if you want to plow through some deep stuff, you may have some problems. In 8" or so of snow, I can't get up my hill in 4wd without clearing a little path and taking a faster run.
I have never used a rear-mounted snowblower, so I don't know how well that would work with R4s. I assume you would be driving through deep snow since the snowblower is on the back. Depending on how deep you get, you may or may not have a problem.
For me, the pros of R4s far outweighed the cons. Everyone's situation is different.
