Need some input on Boss Snow Pushers. I will be buying one in the next few days. Interested in experience with the SK AND SK-R models. My understanding is SK tilts and adjusts to the ground via the mounting system and has a metal trio edge. The SK-R adjusts to the ground via the shies on the box ends and has a rubber cutting edge. I have never used a rubber edge before. I'm interested in what you like and don't like. Any issues with either one not cleaning well? Going on a New Holland Powerstar 75. My father has been dreaming about a tractor like this his whole life, at 69 he finally gets it. I'll be subbing some work to him but I am buying the plow.