I've decided on the L3400, industrial tires. Seems it will be a great machine for my uses, mostly loading materials at my yard (good gravel lot) with some use on site doing landscaping - most likely "excavation" and tilling for new lawns. The dealer will fill the tires at no charge, with, I assume, calcium not foam. What are the advantages and disadvantages to filled tires? I realize that filled tires add weight to the tractor, but would a counterweight on the back (3pt hitch) make up for it?