I have 4 cats. 2 are over 18lbs and they are getting use to it. My orange tabby that is 13lbs loves it. And my 10lb girl has really taken to it yet. They all however, love the scratching posts. Overall it is a very sturdy cat tower and I needed one that would accommodate large cats.  This seems to do the trick. But, if I were to design it, I have made it a liitlle more easier for my babies to jump up and down on it. Like the side shelves need to be wider and the baskets, bigger.