Aloha, for better or worse Hawaii is pretty slow to change. I think it will be pretty much as you remember. All the big landmarks are there ( NS, Ala moana mall, sandies, etc) . The reef is not as healthy as it was 11 years ago, and there are definitely more people, and new stores. Mostly it might feel different because you've aged and gained some experience how life is like in the mainland.

For sure though, college on Oahu is the way to go! When you graduate you can decide to stay or relocate.