When we went on our first cruise, money was a bit tight as there were 5 of us so we had inside cabins on deck 2. It was a bit disorientating not knowing if it was night or day but you don't really spend much time in the cabin, just to sleep, shower and get dressed to go out again
We gazed wistfully at outside cabins as we passed along the corridor and as my son didn't want to come with the next time, we booked an outside cabin for 4 . We felt we deserved a little extra seeing as we were a bit cramped with 4 adults sharing.
We went up to the next level deck 3/4 for the inside cabin.
Our experience of a higher deck is that there aren't so many kids running up and down making alot of noise. As I say, that was just our experience of the lower decks, others may tell you that it was quiet around their cabins.
If you have an inside cabin it doesn't really matter which deck you're on. If you don't mind going up and down the stairs ( good exersise) or taking the lift go for it. It is cheaper.
We now like being able to see out so that's why we go for outside now. We use the money that we would have paid for our son to indulge ourselves