It was really fun, easy and quick to assemble; not like IKEA lol My cat is about 8lbs and moderately active and he's always in the little bedroom or on the 1st platform below the highest one. I don't see how reviewers are saying that this is "flimsy" unless you're assembling it wrong and not tightening those screws REALLY tight or you have a 30 pound cat, if you have a 30 pound, don't get a tree; get a treadmill. 

I dig it, no complaints. 

Note: I tied strings with little feathers around the tree and that actually makes it a little more fun for the cat I think.