My little dog is getting old and having accidents. I have a light colored carpet, and most times the only way I know is when I smell dog pee in the air, and have to get on my hands and knees and sniff around like, well, like a dog. My little dog watches me, not sure what's she's thinking. ANYWAY, I've been using the little green machine but I decided to try this, and so far I am giddy! So nice to just fill it up, set it down, and walk away. Okay, the first few times you don't do that. You turn it on, lay on the floor, and watch the machine do its thing in fascination. But, eventually (maybe the 3rd time) you get up and do dishes instead. ANYWAY, my point is it works great so far. If only there was a Spot Bot that detects pee spots. I'd pay good money for that! ;)