I'm a member, and so far we have loved it. We probably would have done it just for the magazine though as we are such big fans.
If you don't do anything else with the membership but attend the
D23 expo (once every 2 years now) it would be well worth it. Of course it all depends on pricing in the future, but the first expo was $90 for 4 days, and was so chocked full of awesome things that it will be hard for them to come close in the future (probably why it is a 2 yr wait between).
We have also done the D23 Anniversary party at
Disneyland this past March (just happened to coincide with a trip we were already taking for my daughters birthday...FYI, if you look at the recap on the D23 site, the picture of the little girl blowing a kiss to Cinderella is my daughter

she is actually wearing an Alice dress with a brown hoodie underneath, b/c it was from 9 p.m. till midnight, but it almost looks like she is dressed as Cinderella. Didn't even know she was in the recap until we looked it up a few days later, but what a birthday souvenir, a picture on a Disney website!).
For the most part the events have always been great and have been things I never figured I'd get to do. Of course, there is always the possibility I'll be disappointed in the future, and I am definitely wishing we lived closer and could attend more things, but I've loved my membership so far...