My cat has had a little trouble at first with the swinging door, but it was enough for some tests to be OK with it. With a litter of white grains and a good diet, the smell only lasts a few minutes after the cat has done its needs.
The bin is large enough, I have a little kitten and it leaves him enough space so that it lasts a few days before the alert cleaning ...
I have not needed to change the filter after 3 weeks.