We brought the Littermaid Self Cleaning Littler box about 3 years ago. Overall I feel it is a good machine, although it does have some flaws.
First you must use a premium brand of cat litter. We use Scoop Away. After about 10 minutes after your cat uses the littermaid it will rake up the waste and dump it in the containers.
I found that if you accidently overfill it, the machine will jam up a bit. Be careful to fill the litter right between the two red lines on the side of the machine.
When we first brought the machine our two cats were not sure what to think. Our one cat likes to wait and watch it rake up. They did take to using it just fine.
I feel it runs very quietly. There is some minor noise, but nothing I notice unless I am near the machine when it goes off. The machine can run on batteries, but we personally never tried it and only use it as a plug in.
Now, the flaws. It can be a chore to clean. I take it apart and give it a good wash about once every other month. I feel you really need to do this to really get off any old spots and to get rid of any odor.
Another flaw I have seen is sometimes the litter/waste will get stuck on the rakes. That is a real pain to clean up and kind of gross. I found this did not start happening until about 2 years after we had it so maybe the rake just lost some of its strength.
After 3 years of having this, our machine stopped working. The wire that runs to the rake has a short in it so there is no way I can fix this. Currently we have unplugged the machine and are just using it as a standard litter box. We are in the market for a new one. Even with some of the flaws we will get another LitterMaid system. I felt we did get our money out of it and it was a good machine until it starting having problems.