ksss makes a good point; I should clear up what I said earlier.
A leveled truck has more relative sag (relative to its own front end). The absolute sag (inches of rear suspension droop) is the same as factory. The axle weights are essentially the same (vs a factory raked truck) - the geometry change causes a very slight weight shift to the back, but we're talking ounces.
I prefer a non-leveled truck for a work truck, as it retains the factory front suspension geometry. However, it's personal preference. Just make the the headlights are re-aligned.
