TUG is a great resource, and I think the main piece of info you will receive there, regardless of timeshare system you inquire about, is to BUY RESALE.
As Carol mentioned, a lot of TUG is accessible for free. Full access is $15 per year. There is a lot of good info on TUG, but don't expect the volume of responses, variety of opinions, or friendliness that you find here.
There are basically three options to do what you're asking. One is to contact the developer directly (either by phone or by going to a presentation).
Be aware though, that very few, if any, other timeshare systems operate with the level of integrity and professionalism
DVC uses. DVC timeshare salespersons will slant presentations and provide partial information, but they rarely tell outright lies. When DVC timeshare salesmen tell lies or half-truths, we get threads here on the DIS because people are surprised and disappointed. In other systems, VERY high pressure and lying is the
norm, even with large, very well-known companies. Timeshare salespersons are called Sales Weasels on TUG, and their spiels are called Weasel Speak...and for good reason. If you buy direct, you will pay a VERY high price. With DVC, you'll save 15-40% buying resale; with most other systems you'll save 90+%.
Resale is obviously the second option. TUG has resale listings, and listings of resale brokers. Redweek also has resale timeshare listings. And eBay is evolving as the major market for non-DVC timeshare resales. I recently purchased a Wyndham resale on eBay for less than $2,000 including closing costs -- it would have cost $35,000 if I'd purchased direct from a Wyndham Sales Weasel.
The third option -- and it's a good one -- is to rent from an owner. Both TUG and Redweek offer timeshare rental listings, and that's a great way to try out a timeshare before you purchase. If you're only going to be using a timeshare occasionally, renting is probably a better option than buying.