I have two full grown Maine Coons who are on this tree most of the day.  It has withstood all their play and more especially their size and weight for the last 3 years.  It does rock slightly when both of them are going full tilt on the upper two perches but it has never been an issue.  That would be the only tweak to the product which I would suggest would be a bigger base.  I would highly recommend the product and I am about to purchase another one to take to my boyfriends house for them.