It was an easy assembly, and ends up super sturdy! Note: there are two #4 panels, but only one is carpeted - the other is the ceiling of the house. I was doofus enough to complain to Groupon about it, asking how to get a carpeted replacement, then we like "ohhhhwaaaait." No word smells it clunky bits, and it's tall enough to cover all bases of a cat's comfort.
All in all, a very cool cat tree!
I bought this for my 14 lb Maine Coon mix who loves hanging out way up high and rough housing. This went together fairly easily, apart from the written directions being inaccurate. The biggest problems I have are 1) the top shelf is way too small for any full grown cat to lay down on and 2) the middle 2 platforms are not staggered so my cat can’t jump between them. We had to switch the top shelf.