Our cat is full grown (18 pounds), she can't knock it over! It's very sturdy and for once in a lifetime she can scratch at free will and stretch out to full length. Very well made and looks nice. No cat nip required - she took right to it like it was her long lost toy.
Highly recommend it for a full grown cat and of course for all the kittens. 

Pros: Very Sturdy, well made, looks nice