All I have to say is; what a great investment!!! I have to cats; both are 9 months old.... pretty much almost full grown, and they love this thing!!  It has wobbled a few times, but never seems like it will tip.... and I mean these two rough house on it!  They love to sleep on the tall perches, and the fur is really soft.  They enjoyed playing with the toys when they werent attached, so I didnt bother with it; plus they would have been ripped off in a few hours.
This was really easy to put together, took about 20-30 min.... LOVE LOVE LOVE IT!!! My Kitties are in heaven!