Hi Canada - our friends had called a few days ahead to confirm if they had availability. With any of these day pass resorts, just depends on their occupancy rate. Most won't offer them if they are at 80% or higher. Some resorts will only confirm that day. So was nice to be able to confirm ahead of time.
We were there in mid March, so I was concerned we would run into spring break but wasn't an issue. Maybe if your traveling during a holiday week... Easter, Christmas, New Years, or if spring break gets really busy. But this resort is a bit higher budget than spring breakers would normally choose, and not a big spring break destination (like Cancun is).
Highly recommend, I did a LOT of research.. mostly checking out pools. This one has everything from a beach, to one of the best pools, and a swim up bar! Only advice is to go as early as you can get off the ship and snag one of the lounge chairs overlooking the ocean.. just up from the beach so the vendors can't approach unless you wish to shop. These chairs were snagged early.. .tons of chairs around the pool.
Beware the sun is fierce in Mx and you can burn REALLY quickly even when it doesn't feel that hot. Sunscreen and some shade is your friend. Your pool waiter will position additional lounge chairs all you have to do is ask.
Also I recommend tipping a bit up front, always helps service if the pool is busy. So first time I get a drink, or an umbrella, I slip a $5 (also my approach at all inclusives that tips are normally included)....