I'm a charter member and I enjoy it. Yes, the magazine is expensive, but it's very well done and I look forward to it. Sure, in the age of the internet the info is available everywhere else online- but not presented as well as it is here. The club and magazine deal with everything in the Disney universe, not just the parks and not just WDW, so if all you care about or are interested in is griping about the current state of Disney or WDW then you will be disappointed in the publication and D23 in general.
If you are a fan of all things Disney, then it's worth it.
The Expo is fantastic, but then again it is ALL things Disney- film (including Star Wars and Marvel), tv, music, publishing, Imagineering, home products, etc, along with the parks. Seeing the Disney Legends ceremony in person along with stars from the films, the directors and animators of the films is truly worth the time and effort (and expense) to go- especially if you combine it with a goodly amount of time at DL Resort. You have an opportunity to just immerse yourself in total Disney "nerd-dom" for a weekend and meet other folks who truly love all things Disney. Again- yeah, you can see a lot of this on YouTube, but it's not the same as seeing the cast of "The Avengers" in person, seeing Kermit and Rowl sing "Rainbow Connection" in person. Seeing Lasseter intro clips from upcoming animated films, meeting Brad Bird, Dave Smith, etc. Just think of it as Comic-Con for Disney fans and don't expect to see everything- it's very crowded and exhausting. Love it.