I am a first time cat owner and this is my first cat tree purchase.  It was easy to put together and actually larger than I imagined.  My cat was very interested in all the pieces as I took it out of the box and as I added each new layer, he had to "try it out" until last night when I went to bed, he was laying on the top level.  He gets upset with new or different things in the house, so I think he is still getting used to having it around.  Due to its height, it may need more stability because when he jumped down from the top level, it almost fell over.

Pros: Good price and easy to assemble
Cons: Not sure of stability yet