My son was in both. He loved Arndt Park, they have the clubhouse to themselves and the park is right outside. Walk to Iroquois twice a week to swim. Small group feel. Camp Opeka on the other hand, he did not like at all. The hub for both Opeka and Chickagami are under a covered shelter with picnic tables, they go inside the church on hotter days or rain days. The park is a bit of a trek from the shelter. My son would complain of being hot almost everyday. Larger groups and they were bused to Iroquois for swim days.