Having stayed at this hotel numerous times over the last couple years, and read many reviews, I understand (and have shared) certain guests' frustrations.
As brief background, being "contractually married to Marriott," over the past 20 years of my life, I have spent over five years in one Marriott property or another, and currently spend 100+ nights a year between Marriott bedsheets.
From my experience: Marriott used to be in the hospitality business, where it felt as if guests came first. Now, they seem more as if in the business of hospitality, where profits take priority over guests.
The condition of Marriott properties and guest service took a big hit after the financial crisis, dropped even more after Covid, and have never recovered.
Sawgrass is in a great location, which is what motivates me to overlook the negatives I can pretty much expect to experience whenever I stay there. The rooms aren't bad (not like when they let the villas deteriorate 20 years ago), but the accumulation of smaller faults are starting to pile up.
Towel bars are missing. Stainless steel surfaces are pitted and rusting. The shower faucet is about to come off like a loose tooth and the shower knob is wonky. Curtains are frayed. Carpets are stained.
Mechanically, something usually doesn't work. The TV. The HVAC. The phones. The sink gurgles hours after the last swallow of water went down.
The front desk has never been an issue. In fact, I've always found them to be very pleasant and efficient. The valet parking, however, is hit or miss. Leave plenty of time if you're heading out with dinner reservations or to catch a flight.
For those who don't sleep soundly, keep in mind the atrium design of the main building creates a lot of reverberating noise. The hotel is frequently occupied by, let's call them, well-lubricated golf bros away from the wife, who aren't shy about their volume or word choice, and their happy conversation in the bars and restaurants is broadcast upward and will make it through your door well into the midnight hour.
As for other reviewers' trying to reason how room upgrades and room assignments are handled: it seems as random as a lottery drawing. I'm about as high up the Marriott "frequent traveller" ladder as you can get, but more often than not I don't get any room upgrade even if I try to use the free-upgrade certificates I receive every year. In this and other Marriott properties, I've been stuck in plenty noisy rooms with lousy views (and there are quite a few rooms with bad views at this property).
If you're willing to look beyond the faults, this is a fine place to stay. If you're looking for perfection and luxury, you might want to move on.