I bought a 2520 late last year, and one of the main reasons was that I wanted to be able to plow snow, without having to use chains. I also agonized over R4's or turfs, and ended up with the R4's. In my case, they have worked great. We have had a heavier than normal year for snow, and I have had no problems at all.
Asking if R4's work in snow, will get you a ton of different answers, but mostly it's because, hardly anyone will have the exact same conditions, upon which they are basing their opinion. In my case, I have a fairly level driveway, a "heavy" snowfall would usually not exceed 10-12", and any more than a couple of dumps like that would be rare.
Once you get into an icey condition, I don't think there is any tire choice out there that would be much better than the other. I will say however, on advice from this forum, I did go with a ballast box for added traction, and it did make a huge difference.
The R4 tires will be much superior to the turfs when it comes to loader work. They have a much stiffer sidewall, and will handle the added weight of the loader and full bucket far better.
I have also found that the R4's are not really an issue when mowing grass. By the look of them, you would think that they would be hard on the grass, but as long as the ground is fairly dry, and you don't use 4wd or make sharp turns, I find them not to be a problem. You just need to be aware that under certain conditions, you should stay off the grass. I find sometimes they will leave a crosshatch pattern behind you, but this dissappears as soon as the grass straightens itself up in a couple of hours, no big deal.
See pics.....all done with the blade, R4's, and no chains (I do have the ballast box on)
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