Had to take the top off, as my cat ...
589969
Had to take the top off, as my cat is uh, slightly too big for it (~15 lbs).  However other than that he loves it for the price.
2470987
Great new bathroom for my monster cat. The only problem is I had to remove the top. He doesn't like to be confined.
1997001
My cat (16 lbs) won't go in if the top is on. The top is only good after he goes, to keep the dogs from eating his poop.
972302
the cats have trouble getting to the top layer, there is no room between the top hide space and the posts and there is no easy path to the top.  One had LOVES the little hammock feature.  One post came cross threaded and could not be used.  I had to take the top hiding spot off to allow room for the cats to get up there.  The dangling mice are very popular with my cats.
138409
It's great! My cat doesn't like round scratchers, as she's used to scratching doorframe. Did arrive with the top wooden piece detached, which I had to glue back on though.
1215898
Box is good but I have to leave the door open because when one of my cats goes in his head touches the top.  Now he sits with his head out the door.
3609411
The issue with this cat tree is that the kitties can't get to the top?  I decided not to put in the hammock due to having a fat cat :) She was adopted as a fat cat.  The 2nd issue I've had with this is that the top section will NOT screw in the way it is meant to so we have it firmly against the entertainment system so that it won't topple over!  I would ask for a refund but it took me two hours to put it together .... :/ Hopefully, the cats will start using it or it is a complete waste of money and that is horrible on a tight budget.
782254
I bought this litter box because my cat would kick the litter out everywhere and would make a huge mess. He still manages to kick the litter out, but front only, at least.
I would have given this product 5 stars, but there are two things that bug me.
1. The corners were designed in a way that makes it difficult to scoop and 2. The top doesn't snap on the box properly, making it easy to move out of place.
701374
My cat (about 12 lbs) took to this even as I was assembling it (WHICH was not as easy as I had hoped.  Not that it was difficult to follow, but the little plastic "bolts" are hard to negotiate especially getting them into the bottom panel.)

She started to romp and beat up the little mousy with great zeal and was a bit shocked, as I was, when she leaped on the roof to have it collapse as one of the little bolts went flying.

AS we all know cats like to "be on top of things," so I would suggest to the manufacturer that some sort of roof support be incorporated in the design.  An engineer should be able to figure that one out easily.

After her romp, she lay down inside for a little nap.  I bought this because a paper box would work just as well, but it's more attractive in my living room than using an Amazon.com delivery carton, which, I might add, she also adores.
4611584
it works ok. but my cat got so wound up wearing it (kitty stoned) that he accidentally tore it off, which ruined it.
2271824
My cat can open the feeder, so I must leave one of the spaces w/o food
1761023
I love it but the top keeps popping off and releasing my squirrel.
3662591
The two pipes that sit near the top could be sturdier. My cats seems uncertain when they jump up there and it wiggles. The rest of it is great, but I would recommend re-designing how those top two pipes attach.
724463
Well crafted and lovely, fit into my tv room perfectly, however it has a design flaw.  The placement of the half tube before the top enclosed tube and the top kitty bed is at a different angle than pictured...making it to short. It needs to be a parallel to the top tube and it is at a 45degree angle,  or it needs to be longer.  Although my cat, contortionist that he is could use his claws to pull himself into the top..a way down could not be found. To leave the top bed he had to jump to the floor. Not okay.  May have to figure a way to remove the top ..which defeats the entire idea of the tall tree..since it connected the cat to an around the room ledge.  So almost perfect. Chance of cat injury moves this from a 5 star product to a 2. And would not recommend purchasing.
2308689
The cat is fine,  but the ball/stick/string that comes with it got wraped around my three year olds neck. It took a lot of untwisting to get it off. I'm glad I was there.
2790043
This is good, especially for the price. But you should know that the top part doesn't really stay connected to the bottom part. Easy for the cat to knock off, then it gets in the cat's way while it's try to do its business.
4096402
I bought this for my cat to crawl inside of. The picture you show shows the top sitting upright., mine does not so my cat is afraid of it! A lot of the problem is due to the way it is shipped. I received it in a good size box BUT it was flattened, rolled up & taped! How do I get the top to sit up? Very disappointed!