I would never put a dog door in now. But as a child I had one for our 3 golden retrievers. Boxers are such an indoor breed that I don't think they need that freedom. If I wanted my girl to have access inside and out I'd just leave the door open for the amount of time I felt she needed. If you left a dog to there own free will then I sure they'll be going in and out all day long, but my neighborhood isn't set up for a roaming dog. To be honest unless you live on a farm or in the country I don't see how anyone would even let there dog outside with out proper supervision. I realize there are some really great dogs out there that can handle the responsibility, but if you had a 4-5 year old kid that was a really responsible would let him out to play with out supervision for any amount of time. Plus granting them access to the outside is just one more piece of leverage you have in NILF training and giving free access to it might make it lose some of the appeal. But maybe I'm just jealous because one I have a small yard and two I can barely trust my girl when I'm in the shower (JK).