Went together smoothly, although we had to change posts a couple of times because the picture was a little confusing.  Very sturdy tower, but it does need to be secured to the wall.  Bandit is 10.7 lbs, and he has rocked it several times.  Like most cats, he takes the shortcut of going up the outside poles, not slowly level by level.  He loves the hammock and the very top three levels, as well as the mice toys.  He doesn't spend any time on the lower two levels.  I would definitely recommend this cat tower.