Brett,
You probably put more hours on than I do in 6 months. Also your sand might be more abrasive than the dirt in my area. I did a 3 day 300 mile flat out single track ride last season through everything possible and the tire came through like a champ, not too much noticable wear. Mind you that tire was one of the old ones that still said "unadilla" on the side. I put a new "Millville" on this winter but haven't tried it yet. I did notice the tire was a slightly different, same 120 size tire was lighter, narrower in the carcass and across the knobs by 1/2". Hopefully it will stand up, maybe they changed the rubber? Cam.