This piece looks great...on par with a piece of furniture you would want in your house. It assembled pretty easily and seems sturdy assembly-wise. I don't expect it to be falling apart anytime soon...definitely quality materials here. 
I have two big Bengal cats that can easily hop in and on top of the sphere. One loves to hide out inside, the other loves to stand on top. Only small issue is that it's center of gravity is so high (relatively) that the cats manage to knock it over pretty regularly. If the base were wider and/or heavier, it would be perfect.