Most of our seven rescue cats are tall, so we want the tallest high-quality posts we can find.  Sisal is the best material.  Carpeting doesn't last as long.  Cats need tall scratching posts to stretch high.  The ones who don't reach the top frequently climb up to the top after scratching.  Our cats love these.  Can't imagine what our furniture would be like without them.  (They use scratching pads, too.)