COPA is an excellent airline. Used them a few times to fly to Colombia.
They have modern planes and a very good on-time record.
Copa is an absolute ''nightmare'' when trying to make changes of days. They refer your request to another office. The replies can take one or more days. Every person will have a different story and price. Be aware---they charge much more if the flyer cannot fly through MIA(no competition=Dominicans). They particurlarly ''gouge'' on AR flights and other S.A. destinations.
Continental and United are merging