I've only heard negative things about timeshares.
OK, I can give you a positive timeshare experience but it is very limited to the situation and this is not true of most timeshares which I think is a waste of money. If people like the timeshare experience I've always felt - in general - that they were better off just renting a timeshare week from someone...
Anyway, when my kids were small, we went to Walt Disney World and Disneyland several times so we bought into the Disney Vacation Club. We bought a certain number of points and you could use your points to stay at any Disney property and also at a number of high end non-Disney resorts. You had a "home" resort and I think every other trip had to be to the home resort. Ours was at Boardwalk Villa at WDW.
We used this a number of times. We stayed at Boardwalk Villa a couple of times - in a 2 BR unit with full kitchen - much nicer than a regular room. We also stayed at Disneyland once and went to Tanque Verde Ranch in Arizona once. I think we also stayed at another WDW property once.
Anyway, after a few years of this we decided we wanted to go to other places so we sold our unit on the secondary market. We sold within a matter of days for more than we had paid for the share. I was sort of amazed by it because a DVC timeshare was not forever. It was basically good for, I think, 40 years and we had used some of the years. The big thing that held prices up was that if you get an offer to purchase your share Disney had a right to match the price and purchase the shares and Disney would do it if the price was low. So people made good offers. Of course, when we sold our shares, DVC was selling shares (with a full number of years) for more. But the prices had gone up enough that we still received more than we paid.
This was some years ago so I don't know if they still do it the same way or not.
Of course, what made this work was that Disney is a desirable location and the fact that Disney would come in and buy your points if you were offered a low price. I think that most timeshares don't have those factors so I wouldn't consider one.