No question, it is a different cruise. The ship and it's activities absolutely are less important than on a cruise to other places. In Hawaii, since you won't have sea days, and will likely overnight in at least two ports on a 7 day cruise, the ship is much much more like a floating hotel than a destination. Many of the cruise lines organized activities will actually be on land not on the ship.
But hard to top cruising at night past the active lava flow into the ocean.
@OKW Lover