I haven't used this one, but it looks interesting. We tried a different auto-scooping system (we have 8 cats) and had some very "interesting" results. Our big male cat Harley (all are spay/neutered) decided he would jump into the litter box then jump out, so he triggered the clean up mechanism. Once it started he would jump in behind it and do his "business" there, so the clean up rakes would then come back and jam the kitty poop in the system. We decided to go back to scooping (many times a day.)
Click here for a thread in which the Litter Robot was discussed before.
I bought a litter robot. It was the coolest thing in the world and worked wonderfully. Unfortunately, my cats were scared of it
and wouldn't use it. But, my cats were all ferals before they were socialized, so they are frightened easily by weird things. I think a more mellow cat would have no problem.
The nice thing is that they gave me back 100% of what I paid for the robot....they have an excellent return policy. So, if you can afford it (it is a tad expensive) I would go for it!