I admit I was skeptical I was also concerned my cats wouldn't use something that looked like they were going through the Stargate. (Okay it's not a big Stone ring) They love it.  They are so enthusiastic about using the litter box that one one of them finishes it will meow for the other so they can both watch it clean itself.  It is very effective at controlling odor as long as I clean the drawer where the waste drops every other day. I won't say it is silent but it is quiet. The litter box is also solved a problem I had with the female urinating inappropriately if a traditional little box was just a tiny bit dirty. I'm glad I made the purchase and I'm considering a second for a different floor of our house