My son also joined ESF summer camps and YMCA camping.
For my comments, other than English, ESF is playing type, they play two kinds of different sports per day include swimming. My son said the teacher let them play very roughly and they are very happy. He was very tried everyday for that week.
For YMCA, some course is both English and sports, but i think not expect the English standard of some voluntee is good. For children they don't speak English for each other. But they includes more ball games, groups games, A&C, cookery etc.
If you join the adventure camp, they will have one outing as well.
Both are similar prices, around $500 per day.