We have two adult male cats.  They use the cat tree all the time.  They do not really use the ladder, but it makes the whole tree more stable as we have one cat that will leap off the top tier.  We are really pleased with this purchase and feel that it is a great value.  It was very easy to assemble.  It comes with visual instructions.   We did measure some of the pieces with a tape measure for assembly, but it was up in a very short period of time.  All in all, a very good product.