We fulltime (15 years now). We don't care to stay in many KOA's because of the high price, but there are a few that we do. When visiting our daughter there are no other choices and the KOA is well managed and great people. We are there for a week x 2 a year. The other is near a cousin. . . again, really the only choice to be fairly close to him. We stay 2-3 nights there x 2 a year. We joined because almost every year we have accumulated enough points for a "free" night, which is about $58.
We think the membership is worth it. We would be staying there anyway, so may as well get something back.
Dale