I have owned Cat Trees of this height before. My cats had utilized all of it especially the very highest places as cats like to get be at highest points and look down.

The two upper stations are almost not used here and is very disappointing. By design, the upper level is very difficult to get to due to being directly above the step below. Like shooting baskets from directly under the rim.

The only way is to come from the basket step to the left if they balance on the post first. (Seldom use the basket at all.) 

So the upper two stations are almost useless. My cats are very active and athletic and had previously flew up and down all levels enthusiastically. Now, other than the scratching posts, usage is passive and infrequent.