I would choose Nachi for sure. It was the best beach day aside from the cruiselines private islands.
They only allow 100 (I think) per day. It's all you can drink. Water, soda, beer, cocktails, and mock tails for the kiddos. You get 3 course lunch, app, entree, and dessert. You get your own palapas with chairs.
It was a nice, quiet and relaxing day. No one was rowdy and I felt comfortable with my DD a few feet away in the ocean. I would book this again in a heartbeat.

It doesn't matter how many ships are in port it's still the same amount of people allowed.
I'm sure Mr. Sanchos is nice as well but with alot more people.Especially when there are 4 or 5 ships in port.
If you have any questions about Nachi Cocum just ask.