A good review of BA was just posted a few days ago so I assume you read that one. I prefer to stay "in town" so I can walk about and enjoy all the off-the-beaten-path restaurants nightly and be in the heart of it all without such a long walk as the BA is a LONG walk from town. There's also no need to put used toilet tissue in the bathroom trash can at the Casa - it's systems are is designed to take care of it all - Ya just don't want to try flushing 1/2 a toilet paper roll worth down it on one flush.
For us personally, the "waterfront" Casa Mexicana in town is tough to beat and even better when matched up with 3P's for a dive op. We found the Casa about 15 years ago when it was new and have stayed there on every return trip since. It is just as immaculate today as the day it was built. Yes, the Casa is "in-town" so the main road separates the hotel from the water and there really isn't any place to swim in the ocean that I'd care to swim within walking distance but after a day of diving I've seen enough, been wet enough, and am more interested in topside in-town relaxation and adventures after hanging out on the Casa's pool deck or on my private balcony watching the coz world go by while checking out UW photos taken that day with an ice cold Sol in hand... Only decision to be made daily other than perhaps a dive site suggestion/request in the AM is what restaurant we'll stroll to and dine at in the PM... Too many great choices from which to chose! The Casa's enormous legendary breakfast buffet opens at 7AM sharp and is included free with the stay (also available free if you stay at one of the Casa's lower cost sister hotels being the Colonial or Bahia but you'll have about a 5-10 min walk to the Casa from them where the buffet is)
For diving we've been with Tres Pelicanos the past 3 years and are booked again for 2 weeks this December. 3P's dive and stay packages are great deals and we've shopped dive ops in proximity to the Casa for years. I can't beat the price of their dive and stay packages and they deliver the type of dive experience we want. I'll also add that 3P's clout with the Casa can usually get you the best southern facing city-view rooms at the city-view price that offer fantastic ocean views (all the way to the southern cruise port) and rival what the "Deluxe Ocean View Rooms" offer. The only difference if you grab a great city view room is you don't get the super-sized resort towels and in-room robes the Deluxe rooms offer. What do I care? Housekeeping is always around and will give me as many towels as I want.
I say contact Jeanie through 3P's website and see what she can put together for a package. See how it compares to other options you look at. I'll bet after all the research, reading reviews and shopping prices everywhere you'll end up with a 3P's dive/stay package. Once booked you'll show up, check into the Casa, drop off all your gear at the shop (right around the corner at the back of the block from the casa) and never haul or rinse any of it again for the rest of your trip. Each day you'll enjoy a leisurely 35 minutes for breakfast at the Casa's buffet before a 5 minute walk around the corner for 3P's courtesy transport to the boats at 7:40AM and then back. We used to deal with the daily haul, rinse and hang it all on the balcony BS until we found 3P's... Never again!