I have 3 boys. Cubby (18), Osito (2) and Barchen (1 1/2). Osito and Barchen took to it right away. In fact Osito seemed to enjoy it more. After he was finished he would wait for it to turn on then watch it until it was finished. Just watching him watch the Cat Genie was fun. Barchen loved the fresh scent and a clean box. He would wait if the box was dirty until the machine came on (around 8am) and once the box was clean, he would then do his thing. Cubby was, well, what can you do about a 18 year old cat. He uses the Cat Genie when he wants to or he'll go upstairs and use the old box. It is because of him I still have the old litter box.
Now with this in the basement, I don't have to haul 3 trashbags of litter upstairs a week to dispose of. The boys love it because it is always clean and I love it because I don't smell the litter box.