Thought I'd chime in here, my first post. I live in Eastern Ontario, Canada. Just bought a new 520, got it last Wed. Have a 4500 warn winch and KFI 60"plow blade. Also put a windshield and roof on it. We had a good snowfall Fri/Sat with about 8 inches of heavy wet snow. I was amazed at how well the machine moved the snow and I have the stock Vee Rubber tires on it. 24x10x12 and 24x8x12 is what comes on the 520. I also went for a 70km trail ride on Sunday after the snow, we already had about 6 inches on the ground, and it worked very well in the snow.
But I do want bigger and more aggressive tires to raise the ground clearance and go better in the snow and other seasons. So after people sounding happy with the Kenda's, today I ordered 27x11x12, and 27x9x12 Kenda Bear Claw HTR (Radials) with new steel rims with a 4+3 offset, (520 same as 500 with stock 5+2 offset). I should have these on next week and will report back here what I think. After 2 rides and one snow plowing session (I have lots of driveway and shop parking area to clean), I am very happy with the machine so far.