I have only had one kitty and I had a large square litter box with a cover that had a broken latch when I got it. I got Kylie in June of 2001 and I just replaced it with a new one this Dec. I got a booda one but It isn't like the one shown it is simply a round pan with a cover. She has plenty of room, and took to it right away. I saw them first in www.drsfostersmith.com but they didn't have the covers for them and where I have her box a cover is a MUST!!! Its in my closet and if my clothes fall off the hangers boom, its right in there!! YUCK! I found one with a cover at www.petsuppliesplus.com and I have been using the liners that come with it so that should make it last longer too. I really like using the liners, makes cleanup so much better!!
AND
I completely change the litter once a week. It just works out that way!!! And I scoop it it gets stinky if not just once a week!