The biggest issue we've had with this tree is that the bottom piece is not represented well in the photos.  The curve on the back doesn't expand all the way to the wall.  It's simply the reverse of the curve on the front. I had thought it would wedge into a corner and be supported on both sides, but it doesn't stay balanced very well. We secured it to the wall with a hook and wire, and now it's fine.  Had that not worked, I probably would have returned it.

We were also concerned about how in the front it's completely flat, with no space for the cat to step.  However, she's able to jump straight from the floor to the platform above the cubby.