A few thoughts...
Has anyone ever heard of Great Escapes? They claim they are not a timeshare and are a Vacation club?
Never heard of 'em, but in most (...maybe all) vacation clubs you have a "membership" rather than an "ownership" (but all certainly will still have annual fee obligations). The actual usage itself is certainly "timesharing" in any and every other possible sense.
The questions you need to ask of this (or any other) "vacation club", getting answers in clear and specific detail (and preferably in writing) are:
--- exactly what resorts do they have access to (i.e., inventory),
--- in what particular seasons or weeks?
--- details of the actual reservation and confirmation procedure and, last but not least...
--- the annual costs of the "membership" to you.
In my experience and observation, most people who sign on with "vacation clubs" end up reporting being very disappointed with what / where they can reserve --- and when. Disney Vacation Club may be a noteworthy exception, but DVC is really an entirely different (and much more expensive) animal than other "vacation clubs" in the first place...
P.S. It's your choice and prerogative, but this inquiry would likely get much more exposure and response over in the "Buying, Selling, Renting" forum, rather than in the "US-Eastern" (geographically specific) forum...