Dave, congrat's on joining the small fiberglass world. I am sure you guys will enjoy it!
As far as "organizations" to belong to, frankly many people camp/travel without belonging to any. It's about finding what works best for your camping needs.
Good Sam, is ok for discounts and inexpensive enought to have for the times you run across a campground/rvpark that offers a good sam discount. Many privately owned campgrounds/rvparks are choosing to opt out of Good Sam, due to the cost of being able to offer you those discounts!
And instead just offering their own or choosing not to raise their rates, rather than raise their rates in order to cover the cost of giving a discount
. Private campgrounds/rvparks pay dealry to offer you a "good sam" discount........ If your camping plans seem to be in more in areas that are 12 months a year, then more than likely you will see more Good Sam discounts. If your camping plans tend to be in more seasonal destinations than "good sam" discounts may be fewer and farther between. But again, it's inexpensive enought to belong.
Escapee's, hmmmm is ok but more for the extended/full time rv'er! But some choose to join, because they do offer a lot offer as far as information, groups, etc........................
I got to run, I will try and thing of other "organizations" and come back and post thougths. But have to say, it's best for you to take the time to figure out your camping style and then from there figure out what oranizations will work best for your style.