Following a previous review, I laid out all pieces according to size; this made assembling the cat tree much easier.  Pictorial instructions are slightly difficult in a few areas.  The ladder was difficult to insert at the end of the diagram; I loosened the screws inside the cat house, inserted the ladder, and tightened all screws.  My cats love this tree; they started getting on it before we were finished.

Pros: Everything fits well.  Fun for my cats.
Cons: Some difficulty interpreting the last pictorial assembly diagram.