I work at a tire shop, we have put on a lot of AT3's. I have driven on them, and from talking with customers they seem like they have great traction especially in the snow. However they do seem like they wear a little on the faster side.
The LT rated tires come with a little more tread depth. But I seen more than a few 2500 trucks get 20,000 miles +/- from a set (Beat down work trucks, no rotates probably bad parts)
The Mastercraft is the same tire.