My two cats started playing with the tree while we were still assembling it! You can tell this was designed with cats in mind. They love the sisal scratching columns. The dangling toy was an instant favorite. And, we've set the cat tree in front of a window and the second story house is at the perfect height for them to see out and get sun. 

Pros: The house went together so easy! It's great that the columns are all the same height so you don't have to worry about what goes where. And both of my cats are able to sit and play on the tree at the same time (one is ~13 lbs, the other ~10 lbs).

Cons: My cats have their claws so they have been able to pull up little pieces of fleece from the walls and floor. Not enough to make holes in the fabric though.