It is pretty convenient to have litter automatically top off when the L-R runs. When it starts to get low I do need to tap the sides to get the litter off "the ledge" in to the center of the hopper, but overall I'm pretty happy with it.
I really love that it keeps the litter ant the same level inside the litter box. My cats always have a consistent amount of litter to go to the bathroom.
With the LitterHopper, I can go on vacation and not worry about refilling my LitterRobot. I also used to "overfill" which caused the machine to pause. LitterHopper dispenses the litter to the perfect level.