I have always done Veranda. Even on our 3 days. So I have no experience with an ocean view.
That said, on the 3 day, I barely used it. Not sure if it was worth the cost. On a 7 day, it's definitely worth it. The thing for me is when there is a sea day and if I don't have kids with me, sitting out on my veranda can be more peaceful than fighting the upper deck crowds. Not all the time as the upper decks can be nice too. But it can get crowded and the Veranda is a nice quiet place.
I did use it on the 3 day some... I liked to go out and watch us dock if it was on our side of the ship.
Cost not being a factor, I vote Veranda. However for a 3 day, it's a limited opinion.