Something else to look at is how can you end the contract. Some you have to sell or will to someone, others (like mine) I can just walk away if I want. The 14 in, 7 our rule has other little things like if you stay 3 days in, you got to be out 3 days, 4 in, 4 out, all the way up to 7 in, 7 out.
Stay only 2 days and you can move on to the next TT campground. In the last couple years TT has gone through some changes. First they sold the company to an invenstment company, who turned around and sold all the land to another company with a 20 year lease, then they sold the campground membership part to another company this winter.
Other things to look out for, "high use" preserves. They have even different rules like allowing only 2 reservations on the books, only one major holiday on the books, in for the weekend, out for 14 days, etc.
As others have pointed out, there are thousands of different memberships. The one that I got a kick out of is the newer one where I can buy a shadow membership for my kids or parents. Great! problem is both campers can't be in the same campground at the same time.
Out here on the Right coast, the campgrounds are over 4 hours apart. I live Near the hershey preserve. Its so over sold you need reservations exactly 90 days in advance for holidays. I already have my reservations all the way through laborday, but I bet I could not get in there this month if I tried to get reservations now. one nice thing TT has been doing here is leasing campsites off of Outdoor world. We have sites at 3 different outdoor worlds we can book now. Might have to give one a try later in July.
There is a group on Yahoo about Thousandtrails. If you join Yahoo groups, then search on the name you will find it. You have to join before you can read/post I think. Lots of good information, as well as people complaining they did not get what they expected.
all said and done, we enjoy it, Hershey is a beautiful place (all though we have been to others that are just like old crowded campgrounds) We are still young so we hope it stays around a while. We stay around 25 nights per year in TT so we are getting our money out of it every year. (there are 200 campgrounds within 2 hours of our house, and all of them are $75-$125 for a weekend).
we still go other places like the Outerbanks that are "pay" campgrounds. this year we will spend 15 nights there, plus 25 in TT, Not bad for a couple that works full time with a 13 year old kid.