We have four cats who each spend time on this tree every day.  This is our fourth Archie & Oscar tree and they have used them effectively.  They scratch faithfully on the many posts, not on our furniture.  They sleep in the box and on the top levels.  It is in front of a window so they are able to watch the bird and neighborhood action outdoors.  Our cats are BIG (17-18 pounds) and they hurl themselves up this tree and it has always stayed upright.  I am now ordering another because after a few years it gets full of cat hair and the posts scratched up with their heavy, daily use.  I'm happy to buy another.  We put used ones elsewhere, like the basement, so they can still enjoy them.