I did a helicopter tour on Kauai approx 10 years ago. It was spectacular to say the least. Trips go through Waima Canyon often called the Grand Canyon of Hawaii (looks just like GC!). Napali coast is spectacular. Helicopter travel is one of the only ways to see the interior of the Island as I believe approximately 2/3 is privately owned. The primo company is Jack Harter Helicopter - one of the original companies on Kaui. They may cost a few dollars more, but the tailor the trip to passengers preferences. They are also one of the only companies that are allowed inside the crater of Mt. Waialeale.
I have a cruise to HI planned for August. Will be doing the Big Island heli tour this time. Should be exciting.