I have ordered another one for more of my cats.  It is stable with the kind of round base.  I have other cat trees that are not very stable.  The cats like the scratching posts and the scratching level.  They also like the center hole in the bottom house.  They love to get in there and peer out to see what is going on.  It has much better carpet than my other trees.  I would recommend this tree way above any of the cheaper ones.  It is worth the little bit extra.