Day 1/May 8, 2017: Bought this in anticipation for my Savannah cat as savannahs are known for their love for being up high and their rambunctious/hyper personalities. I live in an apartment and space is limited. I figured that this would be a good way to provide a place for the kitties to climb and still save floor space. I also have a 13 lb Maine coon. I just received the product today and chose it for stability/safety reasons as it straps at both the top and bottom. ATTENTION: They HAVE ADDED BUMPERS (pictured) to the product to help with the gap that other people have mentioned with thinner doors. This thing is super stable as my Maine coon just ran up and down it through the internal holes for the past hour. It DOES have a strong plastic smell that was mentioned in prior reviews. I helped my cat overcome this by 1). spraying feliway (calming spray, $8-15 on amazon) into each of the 5 compartments, 2). spraying cat nip spray ($1 at walmart) in every other compartment to promote playing/attract the cat, and 3). by placing some treats on each level. He is LOVING it so far. I do not have my Savannah kitten yet but will continue to update this product review with time and wear/tear/play/multiple cats.PROS:-Very spacious for cats!-Would work well for many cats in a small space. -Holds a large cat(s).-Seems stable.-Easy to put together (less than 20 mins by myself, a 125 lb 5 ft 4 in female).-Many compartments/levels.-Can be collapsed down for easy and discrete storage.-High quality materials. Can easily be used for travelling kitties any place with a door.-Chewy (5 yr old male Maine coon) loves it!-Hoping Leia (14 wk old female Savannah) will love it just as much. She arrives Sat (will post update).CONS:-it's almost too large and kind of disables/blocks use of the door handle on my door.-It's an "eye sore" as my boyfriend put it.-Takes up more room than I thought it would.-Please carefully read the measurements and see photos as they do offer a smaller option. -Strong plastic odor (I hope this will lessen with time and use).