First of all, I am a charter member. That cannot be duplicated. I got in on the ground floor and have all of the magazines. Back in 2009, I was able to read them from cover to cover.
Secondly, I know one of the writers that works with D23. Paul F. Anderson, who has also made appearances at Salt Lake Comic Con and works with the local Disney Club, is a Disney historian. He has done amazing presentations on the History of the Haunted Mansion, EPCOT and the Wonderful World of Weird Disney.
Most importantly, any time I come to visit mom, I have a mini Christmas event waiting for me. While the magazines are beautiful, it is the gifts that really stand out. Magnetic Radiator Springs postcards, an invitation to the opening of Mary Poppins replica, a Walt Disney pen, an 18-month calendar. Every month the magazine comes with some little piece of Disney history, and that makes the entire subscription worthwhile.
While I am happy to pay for my membership, D23 has free membership available, which unlocks some pretty cool stuff on the web. Become a member today and open up the world of Disney for yourself.