rocketman, if you read my post (#736358) in your thread "Which gray do I own", you'll see that the weight issue was the only complaint with the L2201 that I recently sold. I assume your tractor also has the 8.5 x 22 tires on the rear, just like mine. I filled the rears up to axle level with antifreeze and managed to get about 4 gallons into each tire. Though every little bit helps, I hardly noticed a difference and wouldn't do it again. You can guess my opinion of filling the fronts. I now have a Farmpro 2425 with Koyker 160 loader. Equipped as such and with the addition of a box blade loaded with 300 lbs of additional weight, it weighs close to 4000 lbs, which is at least 1800 lbs heavier than your setup, and has a 25hp engine. It also spins all four tires when attempting to cut hard packed dirt. I doubt the result would be any different if it weighed twice as much. What will make a difference is a tooth bar on the front of the bucket. The smooth front edge of the bucket isn't made for cutting. A commercially made toothbar will run you at least $200, but if you have access to a welder one can be made for about $50.
Even though I think filling tires of this size is mostly a waste of time, don't take this as a recommendation to not add weight to the tractor. When it comes to pushing / dragging dirt (and I assume snow, though I live in Alabama and don't see much of that), more weight is always better. Weights hung from the front bracket and balanced with a heavy weight or implement on the rear will definitely allow the tractor to do more work of this sort. I've also heard of some creative ways to hang 100's of lbs from the bottom of the frame and various other points on the tractor. Just try to maintain balance so the tractor isn't too rear or front-heavy.