I have a cat genie which I seriously think is the best thing ever. Essentially, when the cat uses the litter box, it washes and dries the pvc granules, and all of the waste goes down the drain (they recommend either a laundry waste pipe or a toliet, but we also have one hooked up to a sink drain pipe, that took a bit more plumbing knowledge).
- Improved smell
- Reduced dust
- No handling of waste (other than once every 6 month cleaning of entire box assembly)
- Supplies are lighter (we live in a 3 story townhouse, so carrying heavy litter around was annoying)
- Fewer litter boxes (for 4 cats we run 3 cat genies, but should have 5 traditional style boxes)
- Environmental concerns (they say the pellets are biodegradable, but I don't know; on the west coast there are concerns about flushing cat waste w/some of the wildlife).
- Cost (the boxes and supplies are expensive)
- Not sold locally (have to plan in advance not to run out of supplies!)
- Extra electricity/water costs (essentially a toliet flush and 30 minute hair dryer each time your cat uses the litter box).
- The pellets track worse than traditional litter.
- Doesn't handle runny poop well (and one of our cats has IBS, so sometimes has runny poops). It smells terrible, so we run the bathroom vent fan for 30 minutes or so and then it's fine.
Hopefully that gives you a clear picture of what it's like to live with the cat genie litter boxes! I only know of one person who tried it and went back to traditional litter, and that was at the request of his landlord while he was in transition (while you're training the cat to use the new litter box, you leave a traditional box nearby and don't clean it, so it can get pretty terrible for a week or two).