When I bought my tractor I paid extra for loaded tires and thought they were a good thing. Now I am planning to unload them the first time I have a a flat which requires a service truck. Why you ask? For one thing it's not easy to lower pressure unless the solution is below the valve stem - that exposes the interior of the rim to oxygen which can lead to corrosion. The fill also reduces the tires ability to flex which reduces traction. Filled tires are so heavy they are nearly impossible to change or work with by yourself unless you buy some special equipment or a hoist. Lastly, if you have a situation where you don't want the weight (soft soil, avoidance of soil compaction, etc) you are simply out of luck.