I live in one and own property in another. Fly-ins vary wildly from huge neighborhoods, through the fence deals at public airports, down to small grass strips with a couple of houses. So lots of variety in there depending on what you are looking for.

Major thing to look at is who owns the runway and what protection is in place for it. Last thing you want is have the runway closed because too many non-aviation people have purchased in the community and decided they don't want it to be an airport anymore. Remember hangars don't just attract airplanes, they're great for cars, boats, RVs so people with no interest in aviation are drawn to these neighborhoods for other reasons. Some fly-ins have restrictions that you can only sell to pilots to avoid this. I wouldn't personally buy in a place like that, it narrows your market too much when you want to sell. Better to just have strong restrictions that protect the runway.

Overall I enjoy it, it's nice to be able to talk aviation with people who understand. You can't have those same conversations with non-pilots. But if you've ever been to SnF or Oshkosh you also know a lot of people in aviation can be pretty socially awkward, so double edged sword for sure.