Ok. That was the reason I purchased the All Trails also (4 ply). I don't know that the 2 ply field Trax would have held up to some if the abuse that I put my tractor through. Especially when hauling fire wood out of the woods when I am pulling heavy loads and there is often under brush that likes to ruin a good set of tires.
I have been extremely happy with the All Trails performance and don't have a problem with them tearing up grass like your typical Ag Tire does. I would recommend them to anyone considering a HDAP tire.