Materials and hardware are very heavy-duty, so it feels very solidly constructed once assembled. Assembly was very easy, and doesn't require any tools that aren't already included. The carpet is super soft to the touch, and my cats love it. I would rate 5 stars if the base were a bit heavier. It's heavy enough for some cats, I would think, but if my larger breed take a running leap for the top level, it will wobble and sometimes topple.