I have no experience but I have done a lot of research and we are using oahuprivatetours.com for our excursions. They get rave reviews both here and tripadvisor. The cost is very reasonable in my opinion for a family of 4. So much that we decided to do 2 day tour. We are also doing Climbworks for ziplining. We are going to do the usual Diamond Head and Pearl Harbor as well.