We were inside our first cruise, and got a free upgrade to a verandah the 2nd. The verandah was really nice, but I wouldn't pay for it. I agree, you are seldom in the room.
One other plus (at least we thought so) for the inside rooms is that the set up is opposite the verandah rooms. When you enter the room, the "living" area is first (with the couch/desk combination, then the big bed is at the back.
When we were in the verandah room, we were always tripping over the bed because it was in the section by the door. The steamer trunk thing was about twice as big in our inside stateroom as well. Not sure if that's the case in all of the rooms, but it was with us.