We purchased this cat tree for our kitten. Although still a kitten now  months old, we find that after about 4 months of use this tree is rather falling apart. Out of all the cat trees we explored, we liked this best from the description and the pricing seemed fair and reasonable. It was fairly easy to put together and looked like good thought was ut into the construction.
However, at 7 months old, our 12# kitten now rocks the two uprights making it unstable. These have been tightened and re-tightened over and over. The uprights appear to be made out of structurally soft material rather than actual wood or even pressed wood dowels. So a real "fix" is out of the question as screws and brackets will just stall the inevitable.
The physical design is great but not practical in the long run. I can't recommend this product. The picture attached doesn't fully show the problem although you may see the upright slant, without weight, if you look closely.