I was looking for a cat climbing tree that would be very sturdy as my two cats are pretty active, one in particular. I like the fact that the square shape of this one allows it to nestle into a corner, using the wall as a brace. The cats come running into the room and just leap right up to the top levels. It has never tipped over or even wobbled. I rubbed catnip into the legs to encourage the cats to use them as the intended scratching posts rather than my furniture (to some limited success - one of the girls still prefers my kitchen island - I think she just likes to be chased from the room! The entire unit was very easy to assemble by myself. I have knocked off one star due to the fact that the ladder does not stay attached to the unit - the only issue I have had (and it's a minor one).