I absolutely love this cat condo as well as my kittens.  I bough one it over 2 years ago and my cats (Paolo and Penélope) love it so much that they both want to be on it at the same time, they don’t really like the bottom part, I have only seen Penelope 2 times in the bottom part, and that happened only because he was on the top.
So to avoid that they both wanted to be there I got another one last week.  
However I have to mention that it for medium to small cats, mine are 10 and 8 pounds, so I always add some blankets or towels to make it a little bigger for them, especially for him.
The piece it is absolutely beautiful, different, modern and well made, and they love it, that’s all it matters.