I've used both the Litter Maid and Lift and Sift. The Litter Maid is okay for one cat, two tops. If one of them is a digger, you'll be washing it out every single day. Plus I've found the waste trays are small.
Lift and Sift is pretty good. I had that before I tried the Litter Maid. I ended up giving my dad the lift and sift because I needed a covered kitty box for my oldest, Mollie Rose, who digs to China. The only drawback with the lift and sift is you cannot forget to rotate the tray or you'll have kitty litter all over yourself and your floor. Some people say another lift and sift drawback is it can collect wet scoopable litter in between the "squares". To prevent that, spray the tray non-stick spray.