GAP Adventures should be a top consideration for anyone looking for "adventurous" type of vacation, or wanting to immerse in local culture a bit during the tour.
My busband and I have joined GAP tours to Machu Picchu, the Galapagos Islands, and Turkey. Each time, we had a local tour guide who's well-versed, caring and responsive to the group's needs, and always ready and happy to share with us bits of "local experience". Based on our experiences, we'd use GAP again and give a recommendation to our friends.