I lived in AK for 20yrs I never bothered with putting ballast in the bed, but I did on occassion haul heavy stuff, and yes traction was notably better, more evident in the handling than straight-line acceleration, but not enough for me personally to go buy or fill sand bags or salt bags, weight made far less difference in my Ranger than it did in my SD. 500lbs will not really make it any more difficult to stop, I never once in dozens of trips had an issue with my Ranger stopping from well over posted speeds on down with a snowmobile (6-700lbs wet) in the back. I rarely have tires that aren't worn out. If you are commited to the idea 500lbs is most likely excessive and in a ranger will sag the back end and eat mileage a little, something more like 150-200 right over or slightly ahead of the axle would probably be more appropriate. Ideally gravel or rock salt, I find them to be far more useful for getting back onto the road or started moving if you chose a bad place to park than sand alone.