For me, it's always been about the expansive grounds with all the beautiful foliage, lakes, and wildlife - as well as the numerous walking trails and swimming pools - some areas lively and bustling, and others where you can just find a place to yourself.
Initially, I owned at Nuevo Vallarta's Mayan Palace (which then extended to where the Grand Luxxe is today) - then upgraded to the Grand Mayan for access to its Waterpark - then the Grand Bliss which was a little quieter and newer - then the Grand Luxxe so I could use all the facilities and go anywhere in the resort (which at the time was just north of the Ameca River) - now the "Estates" which also includes south of the Ameca River, and finally the "Empire" part of the "Estates" that will be oceanfront (if it's ever built) - so no more upgrades when I go back this year!
I also knew that I might not be able to use all of my Grand Luxxe weeks - so it's great that I pay a "usage fee" only if I reserve a week - unlike other resorts that require an annual fee, regardless of whether a week is used or not.