They certainly are ingenious. But simply not strong enough for my almost 8000# trailer. The fact that they have a lot less strength when more horizontal than when more vertical certainly has been a problem for me when the campsite is tilted. But I hope strengthening the arms with a few pounds of steel will fix that.
And Lippert has told me to try using dielectric grease to stop water getting into the motors (my other problem). So I'll pull the rubber sleeve off maybe an inch or so, lather the exposed motor with dielectric grease and try to get the rubber sleeve back on. We'll see how that works.
IMHO a much preferable design is the 4-corner vertical screw or hydraulic levelers (like the tongue jack). Their motors are more protected from water spray, and their lift capability is not a function of distance from the ground. But they're only found on much more expensive 5th wheels and Motor homes ...