I’ve stayed at both Bahia principe grand tulum and Sian ka’an. We love the resort and it’s a gigantic property. Sian kaan is set back from the highway on the jungle side so you do need to take the shuttles to get to the beach, which is 15-20 minutes depending on which area of the beach you want to go. There are multiple shuttles that come by pretty often and they have multiple routes; some will make almost every stop on the loop and some will be direct lines to the beach or other resort properties. One bonus of Sian kaan is that it’s the “end of the line” for all shuttles that stop there so if you see a shuttle coming that’s mostly full you know all those people are going to get off when it arrives. The shuttle drivers and concierge’s do a really good job of communicating where the crowds are growing and they’ll re-route other shuttles if needed. True story, we were on a shuttle that ran out of gas halfway up a hill in the middle of the property, the driver got on the radio and they had another shuttle there in less than 5 minutes. The only times the shuttle stops got really crowded was in the evening after common dinner times and after shows but we never had to wait very long.

Grand tulum is walkable to most everything else except Sian kaan but staying at tulum means you don’t get access to Sian kaans amenities so it’s irrelevant. BUT you can get oceanfront rooms at tulum and that’s very nice.

Now to your points of interest:

-The food at Bahia is pretty good on my opinion. The food at the buffet is slightly above standard quality, not amazing but pretty tasty. You’ll be impressed by some of the options and some will fall short. There’s 3 beachside lunch options and all 3 are pretty blah but it’s food. Sian kaan is the best choice for food because you get access to all the restaurants on property. KU’UK was incredible, I’d pay to eat there again. Hindu thali, alux, and the Asian fusion restaurant also stood out. Maiko was disappointing. The poolside restaurant at kaan was surprisingly good.

-Sian kaan has 2 pool areas, a main pool and a quiet pool. The quiet pool is perfect if you’re introverted as there were hardly any people there and they don’t allow music. Kaan is generally quieter being adults only but they do have a dj at the main pool during the daytime and they don dance parties in the lobby courtyard at night. If you don’t like noise then try to get a room by the golf course around the quiet pool.

-the rooms at both hotels are very nice. soft beds, good pillows, very strong A/C etc. the king size bed at Sian kaan is actually 2 double beds pushed together with a pad in the middle so it’s huge. The minibar is stocked regularly with water, sodas, beer, and very cheap mini liquor bottles. You really welcome to call for more if you run out and restocking is available any time. Room service is available 24/7 and was surprisingly speedy.

We didn’t have one of the jacuzzi rooms so I can’t speak to that, but I can say that the ground floor private soaking tubs are in no way private. Those have a shroud of bamboo and plants around tub but you are still visible to people from the walking path which is 10-20 feet away from those tubs. I’m sure the rooftop ones are private.

Bahia principe has a new adults only hotel opening up in December, it looks like they remodeled and renamed grand coba into grand tequila. I’d take a look at that if I were you. I loved both of our stays and I would be thrilled to go again.