This was very easy to assemble, which suprised me!  I'm NOT good at putting things together, lol.  My cats run from 7 to 22 pounds, and ALL of them love this!  They have taken turns the past two days, getting to know the cubbies and perches.  I read hundreds of reviews for similar cat trees at several sites, before choosing this model.  I am so glad I did.  I am seriously thinking of buying a second unit.   They did tear the little demonstration toys apart, but they served their purpose of getting the cats curious about the tree.  Very solid construction, very steady even with my biggest cat (who is not exactly a graceful example of cat) jumping on, or off the unit.  Money well spent, I highly recommend this!