I've spent a day on Oahu, so I'm not the most informed on the ins and out of the island, but from what I've seen it's a lot more like the "new york" to Maui's.... Literally any place you' want to be that is not New york. Oahu is crowded (And I went in october, which is low season.) and has a lot of concrete everywhere... Which is odd... Meanwhile Maui has one "concrete" part and it's Kahului, the surrounding areas are beaches, boardwalks and jungle... Which is a lot more my jam than what is on Oahu.
I feel that Maui/Big Island/Kaui/Molokai capture the "aloha" spirit a lot more than Oahu.
God, only Hawaii could make me speak like that