Don't get me wrong, the view is great, whether you visit during the day or at night. The elevator brings you up to the 24th floor in just a few seconds. The elevator is marked red and the first one on the left once you enter the building and make your way through the lobby.
However, do not expect to kill a lot of time here. You can see Kobe from all four sides of the building, but unless you're waiting for the perfect picture, you're done in 10 minutes.