We got a free trial year too, that expires end of this month. I won't be renewing because it's not a fit for our needs. You have to stay a lot of nights to get the value out of it. Either seasonal or full time. We only stayed at two of the TT parks the entire time, as it was a deliberate choice to try them out and at least get a taste of some of that sweet "free" camping LOL. Left alone to a random internet search, those two places would never have been considered. Not that they were terrible or anything. Just that for weekenders like us, there were better choices out there that probably wouldn't appeal to seasonal or full time rv'ers due to cost, or amenities they'd never use.
Are you saying that if you wanted to stay under your TT membership that there were only certain campsites that were eligible?
We only stayed at two, Carolina Landing in Fair Play SC, and Hidden Cove in Arley AL. The latter being the better of the two IMO. They have 3 kinds of residents: transient, monthly, and owners. Transients are members of various levels coming through for a stay then leaving. Monthly is just that: they're long term. Owners have purchased a lot and have a place year-round.
I think my perception of these places has to do with how well the management segregates the different groups I named. Hidden Cove is a bigger place, so more spread out. The owners have all the premium lake view spots, the monthlies are surrounding those, in loop A and some B, with a few exceptions. Those sites being more or less permanently occupied are never available for regular members coming through. Due to human nature of "taking root" when stationary, those sites are also the ones with obviously stationary rv's that seldom if ever move, permanent decks/porches, lawn furniture, and other assorted crap on their sites only a long term resident would have. It gives off a trailer park vibe, that isn't the sort of vibe I am looking for when staying for a few days. I'm not hating, it's just how people are. The longer you stay in one place, the more likely you'll invest the time and effort to make it more comfortable for yourself.
Hidden Cove did a much better job of keeping the short term folks in the newer loop C near the pool, and the long term and owners closer to the lake. It definitely had more of a campground vibe where we parked in C-66. Carolina Landing is a much smaller and congested park, with the long term folks more spread out. Truth be told it was just as functional as the other, just less convenient getting around inside and more hilly/uneven. Poolside experience at both was about equal.
So it's really not a case of being "eligible." Due to the first come first serve method TT uses for check in, those lots are just never vacant for short term visitors to drop into. For some folks that want that special lake view or beach access site, accept that you'll probably never find one available and maybe a different park or resort with advance reservations would be more suitable for your camping needs.
On the other hand, if your rv is more of a residence and you're on the road a lot and need a full hookup site for weeks or more at a time, TT is a really great value. Nothing about the two we tried was so bad I'd never stay there again. I just probably won't because there's more interesting choices with different amenities and attractions that I'd rather spend my limited camping days at instead.