One of our guys isn't too athletic (big pouch) so I looked carefully for a tree that would give him the ability to 'staircase' his way to the top. I also wanted the resting platforms to have 'lips' because both guys like to have a little boost for their paw-pits while relaxing. This all worked out very well. The two-opening condo is a favorite also. Great price to boot. Kudos to the designer of this unit. The tree is solid and very easy to assemble. It does rock a little bit when the guys jump aggressively, but it doesn't seem to faze them at all. I've become a big fan.