Absolutely spectacular panoramic views once you reach the top. Just watch your head as you climb to the top. After a nice workout climbing Diamond Head, this is your reward. A view, nice breeze, and sometimes a rainbow. Well worth the effort to get up.
One of the most disappointing aspects of this experience is the large quantities of trash littered along the side of the mountain. :( Please people. Take your trash and empty water bottles back down with you. Your water bottles were full when you started the hike. You most certainly can easily walk back down the mountain carrying an empty water bottle.