On the rooms (in terms of UG order) ... it goes:
FM Room (the 4 story "hotel" building)
FM Deluxe Room (also, the 4 story building, with better views)
Deluxe Casita (generally the lower level of the 2-story casitas)
Signature Casita Room (upper level of casitas, view of some waterway - the signature casita suites are basically two of these together, atop two rooms)
Beach Area Casita (I believe these were all lower floor casita *near* the ocean, facing the mangroves)
Beach area not worth it, IMO. The walk there was great, but we liked being in the middle of the resort. For that reason, we saved our suite upgrade for another property...
On the food...
My husband and I are not all-inclusive types. We did one ONCE and found ourselves longing for other options (and eventually just going outside the resort because we liked the food so much). For the same reason, I would never do a cruise.
But the inclusive option here is different - #1 It's the Fairmont: simply put, standards are high and so are the prices. It was a super-relaxing time, ordering whatever we wanted, whenever we wanted without having to think about the bill. And the food was great! We are really, really picky... and skeptical. But we were quite happy with the amazing food. #2 No buffets - ok, you can do the breakfast buffet at La Laguna (where they will also make you eggs, tacos, pancakes, etc. to order) but you can also order off the menu. I liked letting the chefs just make me something - if I didn't like it, then I'd try something else. #3 Beverages: if booze is your thing, or maybe just fresh-squeezed juices and elixirs, the sky's the limit. I think that champagne (over $25/glass) and bottled beer were the only things not included. Yes, I tried the giant boozy coconut drink on our last day... I was curious.
Full disclosure, we stayed for 5 nights. Maybe I would have grown bored in another day or two, but it was just easy and very delicious. We loved the Mexican food at La Laguna and Asian-fusion at El Puerto the most. We are planning to go again next spring.... might bring the kiddo next time, but we may keep this as just a relaxing adults-only trip.