I have my tires loaded (about 600# each) and have added
EZ Weights . I also have a counterweight available for the3ph. For most applications, the fluid and EZ weights are adequate. But if I am using pallet forks and carrying 1/2 cord of wood, the rear lightens up. For that reason, I hook up the ballast.
When mowing, I remove the loader and EZ weights (5-10 minutes) and hook up the mower. I mowed yesterday (after 1/2" rain the night before) and the front tires left more marks in the grass on the corners than the loaded rear tires did.
If you decide to load the tires, do it with them on the tractor. I couldnt imagine having to reinstall a loaded tire. Of, if you don't own it yet, get the dealer to do it.
As JMIII implied, safety is what it is all about. The main advangtage of loaded tire is keeping most of the ballast BELOW the axle, thus lowering your center of gravity. I have to believe, also, that loading and wheel weight are easier on the bearing life because the weight in not on the frame.
Just some thoughts....
Mark