I'm late to this thread - been traveling lately. I took 3 friends to the Vidanta Grand Luxxe in Riviera Maya the 1st week of May and my daughter-in-law to the Vidanta Grand Mayan in Puerto Penasco 2 weeks later to celebrate her birthday.
We bought our first timeshare in 1991 and started our timeshare journey. We bought and sold several over the years on ebay. The Vidanta ones really leveraged us to get into the upper levels with their "equity". I learned on TUG how to find bargins on eBay an then use them for trade-ins. (I was a TUG member on the old system, soon after buying that first timeshare and learned how to make great deals buyin on ebay from Fern Modena.)
I still have one Vidanta week to use this year and have reservations in November at the Mayan Palace at the PV Marina area the week before Thanksgiving. Because I am 78, I get to use my 2 Vidanta Grand Luxxe 2-bedroom weeks for free until January 2033 and I can get extra weeks by downgrading to lower levels. I have used one GL 2-beedroom and one Grand Mayan 2-bedroom so far this year, so the MP 1-bdrm week in PV will finish up this year. In 2033, I will not renew by paying 10 MF upfront because I doubt that I will have 10 more years of use as I will be turning 87 the month the renewal is due. I will take friends with me to the Vidanta resorts until my contract expires because my son does not like the "mega" resorts - he prefers to rent a house wherever we go as a family. If I do get to use my "free" weeks until renewal, I will have recouped all the we paid over the years to purchase Vidant weeks.
I have 2 more years at the Buganvilias in Puerto Vallarta and will not even talk to them about renewal as I will be turning 80 about 6 weeks after my last week of usage. While it is not the most upscale resort compared to Grand Luxxe, it is really nice and the location is amazing - you can get out and about so easily!
I also have a Pueblo Bonito Emerald Bay in Mazatlan - a 1-bedroom 2-bath unit that I bought for $400 on ebay years ago and generally bank it with SFX, and let friends and family go someshere on a Guest Certificate. Next year, a daughter-in-law and I are going to go there for her birthday in late April. She and my son went several times, but I generally used it to get an extra week at the Buganvilas for less than the usage fees for an owner's bonus week. It ends in 2030, but when we go I may see if they will just take it back because of my age. If not, it will continue to be a SFX week.
But, after all these years, I am just hoping that my friends who are about 8-11 years younger than me will want to go for one or two weeks a year to my free Vidanta weeks!

Then I will be done, but will have had some great adventures timesharing.