I have two burmese and a Litter Robot that I've had for 2 1/2 years (I think) with no problems that couldn't be solved by adjusting the sensitivity.
I decided to get the automatic cleaner is because one of mine feels he must dig to the absolute bottom of the box to pee no matter how big the box and how deep the litter. This means that every time the thing needs to be scooped, it needs to be completely emptied and washed, which is expensive and time consuming. This is compounded by the fact that if he does not 100% approve of his potty, he will find a potty that he does like elsewhere in the house
. I read the same site as Lauri and tried a similar set-up, but it did not help me.
The Litter Robot is fairly big - a similar footprint to a regular litter box, but it's tall - and a bit noisy, but I love it anyway. My picky cat has not had an incident since I got it. The cats get in, do their business however they like, and 9 min later the whole thing rotates and the mess drops into the base that I've lined with a small garbage bag. No smell at all, even though the gasket that is supposed to prevent odor escape fell off long ago.
If I change out bags and refill the litter every 3 days, it works like a charm and I never touch litter or a scoop. If I forget, eventually it fills enough so the waste gets smeared on the outside of the rotating top portion which is disgusting and requires scrubbing the whole thing. You do not make this mistake more than once, trust me.