Our trip was similar to yours. 3 days in the rain forest and 6 days on AC. Me, my husband and the two kids all took Aralen. No side effects, and safe enough for kids. We did spend one day in Guatamala and hiked five miles into the jungle. I was glad we took it, even though the mosquitos were not bad at all. We were there during the tail end of the dry season. The rainy season starts the first of June, and the mosquitos get worse. I had a scientist who's excavating some of the ruins in the south, tell me that, the effort at taking the Aralen is nothing compared to malaria itself. He said if you ever had it, you wish you were dead. I was glad we did!!