We've had our Litter Robot for over six months now and it still works like the day it arrived. Beau and Sunny (males) both appreciate it's cleanliness and right-on-schedule cycle 7 minutes after they go.
I change the bag about every five days or so...it's gone a week, but with two cats, it's pretty full at that point. It's VERY easy to change out the bag and cleans up in a second. A couple of times I've put too much litter in it and it stopped but as soon as I removed some, no problem. The recommended amount is about 10 lbs., anything more and it can't "center".
Best of all...there's hardly any litter odor!! Woo hoo!
We've had two Litter Maid cat boxes (both eventually replaced after having to deal with the worst customer service ever!) and even the replacements quit in less than six months...what junk!
We liked the Litter Robot's 18 month warranty and have found the investment worth it!
We can highly recommend the Litter Robot to anyone with one, two or four cats! It's built very well and works great.
Thanks!
Rich