I have the cat-it (picture 3) but with the flap in - it's been removed for that picture for some reason, which kind of defeats the point if you ask me.
Since it folds all the way back so the opening is as big as you see in the picture, it's super easy to clean, but with the top down (and when I remember to buy one, a filter in) and the door flap, and a mat in front of it, I never see any litter around the house, and I have one cat who tries to dig his way to china through it.
Upstairs I have just a big tall IKEA plastic bin, and that works okay too - It's tall enough that even inside sitting on the litter, the sides are taller than the cats. Before that I had a shorter one, and he was constantly tossing litter over the side of that.
That said, both the cats will only poop in the cat-it (covered, with a door, all the things cat's supposedly dislike), so that's where most of the digging goes on. Go figure, cat preferences.