We've purchased other cat trees in the past that we had to return because they were too flimsy. This one is great for our 11 pound, very active cat.  Because it's not wobbly, she feels comfortable climbing all over it. I like the height too.  High enough that she loves it, but not so high that it's over my head.  Great item.  

Pros: Sturdy enough for an adult cat
Cons: Can't really think of anything