As soon as I opened the box the cats were inspecting the parts and I had to keep shooing them off as I was assembling it. Even my 15 year old cat enjoys jumping  on to the lower levels. The little "house" part is a little too small for either of my cats to enjoy, but the certainly take advantage of all the platforms. The structure is very stable and well made and everything needed to assemble it was included.

Pros: Easy assembling, durable, cats love it
Cons: None