My wife and I recently took a trip up to Williamsburg, VA (about a 3 hour drive from home) for a "free" 2 night stay in exchange for a timeshare presentation. We had been to one of these before (see my post from June 2008) and figured it was worth our time in exchange for free lodging + $75 visa gift card.
Overall, the place was reasonably nice -- although to call it a "resort" is a stretch. It was more like a 2 BR townhouse I would expect to see in a typical suburb. But it was a comfortable stay and didn't cost us anything.
Throughout the process, what bugged me most were the half-truths of the time share presentation. The salesman kept making his pitch saying that every year the vacations he takes only cost $140. My wife and I had agreed before hand that the way to get out of there the quickest was to just agree and let them keep going -- so we both had to bite our tongues several times.
I've done quite a bit of reading on timeshares -- and one of the best sources out there is a forum called tugbbs.com. So if you are looking to learn, that's a good source.
Timeshares aren't necessarily a bad thing, IF you know how and what to buy. I would only suggest only buying resale (not retail) since you can get most of them for free upfront for taking over the maintenance fees (as opposed to retail prices of $15,000-$30,000). So if you are considering it, here is the real cost breakdown per year.
Any amortized up-front expenses (If you buy resale, this should be near 0.)
+Yearly maintenace fees. ($500-$700)
+Points network dues. (~$150)
+Points network exchange fee. (~$150)
Total $800 -$1000/year.
If you know you will take a 1-week vacation every year, this may be a good fit for you. But you should also know that you can rent timeshares from current owners for almost exactly the same price as owning -- with all of the benefits -- and none of the downside. So to me, renting a timeshare is the way to go.
To find timeshare units for rent, check sites like http://tug2.com/timesharemarketplace/ or http://redweek.com.