Hello MiSmitty and welcome aboard!
Am not familiar with the Resort system you're researching, but did look into a couple others last year. Colorado River Adventures and Thousand Trails (and another that slips my mind). ALL wanted a fair chunk-of-change to join, plus one STILL had to make advance reservations, no guarantees for a nice campsite when YOU wanted to camp, time limits for length of stay...
Wow...to us that sounded just like what we normally wrestle with.
Best advise: talk to other members AND visit a couple of their parks. Don't be pressured to part with your $$$. We were immediately approached at a 'member park' we stayed at for free (yes, listened to hours of marketing)...by others who wanted to 'sell' their memberships, even at huge losses.