We bought this pen to help contain our golden retriever puppy. We like just about everything about it. It's easy to assemble, configure, and remove or add panels. Also, the pads at the bottom prevent the pen from scratching our hardwood floors.
That said, the doggy door is REALLY small. Within about two months of bringing her home, our golden retriever puppy was too big to go in and out of the pen through the doggy door. It isn't hugely difficult for an adult to open and close the pen by disconnecting and reconnecting a panel. But, it isn't particularly convenient, either -- and our young children aren't able to do it. We later learned that the panels from this Petyard are interchangeable with North States' BABY Play Yard, which comes with a large (human) door. So, we bought a 2-panel door extension from a Baby Play Yard, and we're using it with this Petyard. Ultimately, it would've been better to just by the Baby Play Yard in the first place.