My mother bought me the Cat Genie this past Christmas. I live in a one cat household, but my boy is twenty pounds and very large. We are all in love with the Cat Genie! We set it up in January and didn't have to change the first cartridge until May! I have saved so much money on litter, and I don't have to deal with the terrible litter box smell any more!
My qualms with the Cat Genie are few. One, when it misses a little kitty poop and said poop goes through the dryer, it smells terrible! I'm not sure, though, that this particular issue is an easy fix. I also had some trouble with the water intake valve leaking because it wasn't positioned properly. Lastly, and this isn't Cat Genie's fault, but my laundry room is tiny and the Cat Genie takes up a lot of space! Other than that, I LOVE my Cat Genie!