Automatic Litterbox Central

... they seem awfully similar to me.
What are the advantages/disadvantages of one over the other?
Do i must use the proprietary crystal litter with them; or can I use any clumping litter of my choice?
Is one quieter then the other?
This one might be a bogus question but i feel i have to ask: The litter trays (from the images) seem a bit low ... looks like they might be lower or are just about the recommended 2 inches high; is it filled all the way?

Thanks for everyone's time.

-a

I used the scoop free for a long time after it first came out and I loved it when I had one cat, but once I got two cats the box could not keep up and I had to change it more then once a week! (or I would scoop out the poop because the area that stores it would over load)

You can not use the scoopfree with normal clumping litter it gets stuck. But with the crystals it works nice. I also used a "forever tray" instead of the cardboard trays it came with since my cats would pee ALOT and it would soak though on the cardboard trays (although they did recently fix the cardboard trays to be lined with plastic now) but I also didn't like all the waste with those trays.

For one cat the system is GREAT but for more then one it was horrible.

I've used the LitterMaid and the ScoopFree and there are pros and cons to either system. The biggest problem I had with the LitterMaid was that the waste receptacle would quickly fill up (with two cats) so leaving my cats alone for a week was pretty much out of the question. I worked around the problem by positioning the box on the counter top in my laundry room and hanging one end of it over the utility sink. This allowed the waste to scoop directly into a small trash can in the sink. It worked like a charm -- or until the rake failed. Unfortunately, I had to replace the box and the new box failed within a few months so I made the decision to switch to the ScoopFree.

The ScoopFree is pretty awesome if you only have one cat but less stellar if you have two (or more). I have two and one of them pees like a monsoon so the crystals reach their max level of saturation in less than a week. And that poo trap is absurdly small but since the crystals need to be constantly replaced, the tray is always being emptied anyway. The trays are very expensive but I've reused them by just replacing the crystals. Recently, I took on the challenge of seeing if I could create an improved tray (deeper) and extend the time the box could be left unattended. I wrote about my success in the ScoopFree section of this forum so I won't repeat the whole process here.

Bottom line: I prefer the ScoopFree. It takes care of the smell better and the system is more mechanically sound. I've used my ScoopFree for longer than I used both of my LitterMaids and the only failure was when the motion sensor 'eye' got dusty and stopped triggering rake. It took me some time to figure out what was wrong but it was easily corrected. By the way, if you use premium crystals, they're much less dusty and they seem to perform better too.