Overall great, and I would buy it again. But there are two sensors in the middle of the box. If my cat buries his stuff in a big pile of litter, it blocks the sensor and the rake discontinues working. I took the cover off and it seems to happen less frequently now that it's off. But think about it, if you leave the cat for several days you can't be confident it will continue to be cleaned, so you'll likely have to leave a conventional litter box as well. Aside from this issue, it really is an amazing product. So nice to have to only deal with the litter box once a month or so. And the issue I mentioned above is quickly fixed by taking a scooper and smoothing out the litter.