The only thing a credit card is required for is at check in, for the $300 deposit which is not submitted till you check out and then only for what you have charged back to your room. Other than that you will not need your card while on Couples property. And while credit cards may be accepted at many places off the property, they may not be accepted everywhere. That is the reason that most of us bring a stash of cash along for "extra" expenses off the resort. Also keep in mind that you can very easily spend your entire vacation at Couples and not spend an extra dime at all. Bring some cash to cover the tips for the shuttle drivers and red cap baggage guys at the airport. You will not need to tip anyone else unless you go off the resort. (You should also tip the spa staff if you use the spa facilities)
Where do you plan on spending any money at? If it's at the airport, either is fine. I don't know about you, but I have trouble in the states using my Amex card because a lot of people don't like to pay their charges so I usually just bring my Visa. If it's a bank card, I would call and give them a heads up. We had our card denied because they thought it was stolen and trying to be used fraudulently. We looked a little silly but luckily we had another card so that we could bring home our rum cream!!
It is a good idea to let you credit card company know that you will be traveling out of the country. We ran into difficulties on a previous trip when we did not... And Capital One does not charge foreign transaction fees.
Amy- we took our first trip to CSA last septmeber- and i paid for everything with my Discover-including gift shop items at the resort. When we reserved our trip this year (thru the website) it would not take Discover- so you may need to look at different options. mike