I've been using this as a little indoor yard to keep my puppy contained while I work, and the door panel is what sold me since I don't have to lift him over the top every time. The panels snap together tight enough that he hasn't pushed them apart yet.
The molded plastic panels feel really solid, and my terrier hasn't managed to budge it once. I love that I can set it up as a hallway fence or just open the door when he wants out
The plastic panels are sturdier than I expected for molded material, and the built-in door makes it so much easier to reach in without lifting my puppy out. I use it as a small yard in the living room and it folds flat when guests come over.