At the time of purchase, we had 3 large adult cats and wanted a good, solid cat tree for them. This being somewhat more expensive than other scratching posts, we did some research and found excellent reviews of the Armarkat trees, which influenced my decision to buy one.
This is the model we settled upon, and the cats loved it from the moment we started assembly. We have pictures documenting "testing" at every stage of assembly. They use it constantly. We now have 1 adult cat, 1 catling and 1 kitten, and they all use it to scratch, sit, perch, play and run. (The kitten climbs up to the top using the posts, unlike the bigger cats who just jump up from level to level!)
It is now 3 years later and it is still going strong. Even with the enthusiastic up-and-down chasing play of the kitten and catling, the cat tree remains sturdy and has never even come close to toppling (to answer another reviewer, who felt it needed to be attached to the wall). One of the lower posts is beginning to show some wear, but I know the company sell replacements. What we'll probably just do is rotate some of them around first.
In short, we are all (humans and felines) extremely happy with this product. When it eventually becomes too worn, we'll happily replace it with another Armarkat cat tree.