The cat tree was very easy to assemble and I had four furry supervisors eagerly watching the entire process.  It is very stable and my cats were all over it as soon as it was completed.  The covering on the bases is a fleecy type material that the cats love to lay on.  The only reason I gave it 4 out of 5 stars is that I wish the cubby was a bit larger as it is a bit of a snug fit and two of my large boys cannot use it.  The sisal twine posts are great, however, and my cats no longer have to compete to use a single scratching post.