it is strong and sturdy, easy to put together, kind of puts it self together by unfolding it. dont know what others are talking about with the up and down door with issues, I have just a single door and it slides with ease up and down and rests on top. there are no sharp edges as mentioned in other reviews. i have a 55lb dog, and its solid for her, no escaping. i think the door resting on top makes it more like a room with an open door instead of a cage for her. I put her bed in it and she just lays in it on her own. I only close the door if I go out and leave her in the home, My dog has separation anxiety if I leave, she destroys the house trying to get out and find me. But the cage in my room with her bed, I think she feels ok , safe in there alone.. love this cage. dont think its an easy travel, but dont plan on traveling with it. 5 stars all the way. well , my dog about 50lbs and three days later has gotten out each time by lifting the gate...and pushing her body thru, i thought i had it figured out by placing bungy cords thru the door so it could not be lifted, again she broke the welding of the bottom bar that the door clamps into and with the bungy cords in place everywhere but the bottom hinge of the door , she managed to push the bottom hinge up and breaking the bottom bar from its welding , giving her maybe 5 or 6 inches and slide out ...shes bent the metal bars of the gate or door along with other pieces. She has separation aniexity bad , giving her the strength to do what she does as the bars are strong. I think if you had a normal big dog without the obsessive need to get out the cage would be great. i still cannot believe she slid her hugh body out at the bottom of the door with maybe 5 inches after she broke the welding from the bottom bar.... is it the cage, it might be my dog. I also think they should have a latch not allowing the door to be raised up without latching it not to do so. Well I zip tied all the corners of the ends so they cant be pushed out or bent,,, and bought caribeaners that screw together to place on the door so it cant be pushed up or out for her to bend it and out she goes...so if this works and an easy fix you wont hear from me and the cage is a 5 again. the metal bars are strong , cant imagine how she bent them to squeeze out of the bottom of the door gate. im sure any cage would not of worked as this one was so strong and sturdy as opposed to others and why i bought it. will know tomorrow..lol. wish me luck against the hulk dog.