Bruce is right.
While I don't get very much out of the Sport Aviation magazine because I'm not a homebuilder, and I don't go to Oshkosh as much as I used to because it's become so impersonal and commercialized, we shouldn't forget what EAA does on behalf of all of general aviation.
In the '70s they did the work and proved to the FAA's satisfaction that most of our older airplanes can run on auto gas. I couldn't have flown my J3 to Alaska (legally) without that!
In 1979 or 1980, when the FAA was trying to bring a whole lot of airspace under positive control after the 1978 mid-air in San Diego, the EAA got about 10,000 of us to write personal letters objecting to it. (AOPA was part of that, but my impression at the time was that it was mostly EAA members that had spoken up.) As a result, we got fewer, smaller TCAs, and a transponder exemption for non-electric aircraft that allows me to fly my J3 close to home.
Most recently, EAA has given us the Light Sport and Sport Pilot rules that may allow me to continue flying my J3 longer than I otherwise could. My AME, who is on a first-name basis with the bosses in Oklahoma City, was dead certain that the brass would never allow medical self-certification for powered aircraft pilots. But they did, because of EAA's efforts.
AOPA does other things, just as important -- like providing vast amounts of information and services for GA pilots, keeping close relationships with the US legislators who can most influence aviation law, and right now, fighting user fees (again).
These two organizations are our strength in Washington; without them, the airlines, who (I believe) are coming to see GA as a threat to their business, would have their way with us. Without them, GA here could start to look like GA in Europe, which I've described a little bit elsewhere in the 170 forums. I think anybody who flies small, older aircraft should maintain membership in both organizations. Period. In our own self-interest.
Sorry for the lengthy message, but that's my story, and I'm sticking to it!
Best Regards,
John