This is a neat idea for a cat litter box! The trouble is there is nothing to stop the cats from tracking litter outside the box. And you really can't put it just anywhere because there is no mistaking the horrible smell when your cat uses the box - so I would never put it in a living room. It would be neat in our 3-season sunroom though because we let the cats hang out there when it's not too cold or hot. But I'm not going to buy a new litter box when we already have a perfectly good one. But if you are getting a new cat and need to buy a litter box, it's worth considering.
The litter box we recently bought to accomodate our 3 cats and keep the odors down is a new extra large dome clean step Booda Litter Box. Shown below to the left. We love it and most importantly so do our cats. Of course no mere litter box can stop the odors from our male cat, Alex, when he makes a nuclear waste heap. I have to get up and immediately scoop and flush. But with the dome and the little pathway built into the box, I don't have to look at it and it really does reduce the tracking - better than anything I've tried so far. I was sure my cats would crawl through the tunnel to use the box, but they seem to really like the privacy of it.
The new Tidy Cats Small Spaces litter really helps too. It smells nice and orange. And I don't smell the litter even when I scoop it out now. So I have a new favorite litter, too!
Here's my previous post with more info on organizing cats and pets.