We used the Andersen Levelers all the time on our 5-6K lb travel trailer.
Used them less on our next rig...a 9-10K 5er
Don't use them at all on our current 5er.
They create stability issues, can tend to slip from time to time when setting up, and will sink into softer ground. The way to keep them from sinking is to place large boards underneath them...which at that point why not just use lumber anyway for leveling.
Currently, we use various pieces of 1x's and 2x's and sometimes use the lego blocks. That's all I anticipaite needing ever again until we upgrade to an auto-level system.