Since you are staying at a MVCI property (Marriott Timeshare), you probably aren't going to see much in the way of elite recognition. Upgrades are very rare at these properties as Marriott doesn't have nearly the inventory control at timeshares that they have with a general hotel. And the owners staying there would probably be the first ones to get any type of upgrade if there is one to be had. And MVCI properties don't have lounges and the free breakfast benefit (for weekdays) doesn't apply to these properties.

As a Plat you should still get an arrival amenity. I think most MVCI properties may only offer points (though I think there is a recent thread here that mentions some are starting to offer other options now.) Here is an existing thread on this very topic: http://www.flyertalk.com/forum/marri...-benefits.html

It has been a few years since my last stay at the Grande Vista property, so I don't have much to add on what rooms to ask for.