Most any of the discount programs are well worth while IF you use the associated parks and services often enough, but if you don't plan to do business with them, it's just a waste of money. Focus on where you want to go, then see if any discount programs are available for the park you will use. Most of them are on an annual basis anyway, so you can adjust as your travel plans change from year to year.
We use Passport America primarily for overnight stops, but our travel is mostly weekdays so restrictions are rarely a concern. We re-joined Good Sam last fall after realizing that a couple parks that are convenient to our usual routes to/from Maine are GS parks. The 10% GS discount wasn't enough to offset the cost of membership, but they gave us a free night for re-joining and that tilted the scale. Probably won't renew that one. We have a Thousand Trails membership and that used to save us a bundle, but now we travel differently and don't use their resorts enough to justify the annual fee. Thinking of selling that one off (it's a lifetime membership deal).
The point of all this is that a discount program that's great for someone else may be worthless to you, and that you should avoid long term commitments to a discount program until you are very sure you will get long term benefit from it as well.
Former owner of 2004 American Tradition and several other RVs
Home is in the Ocala Nat'l Forest near Ocala, FL
Summers in Black Mountain, NC