My thoughts pretty much echo Nita's, but our experience (for what it's worth) is that if we are doing Alaska we would definately get a balcony. Not only is the scenery fabulous but there's this occurance called "glacial seltzer" that you can't hear from the public decks, only a balcony. If we can get a balcony at a terrific rate in the Carib. we'll take it but to us it's gotta' be a real deal. Hubby also loves to sleep in a cave, so for him an inside cabin is heaven (we live in the sticks and I have no window coverings in the house).
We spend very little time in our cabin (and there are those who say if you have a really good cabin you spend more time there - point well taken) but some of that's because we're people watchers, and on your average day there are just the two of us in our cabin! but even times when we've had a balcony we still had to leave it for excursions, meals, shows, the casino, the pool, the spa. And while I make a mean drink, I do enjoy chatting with bartenders and other cruisers around the ship. I enjoy my afternoon cocktail in the cabin with DH but I don't want to hang out there all the time drinking, ordering room service, watching movies, reading and playing gin rummy with DH (I'd rather beat him out in public!)
But back to some of the other relevant issues. Compare your TOTAL price, not just your cabin. How much is your vacation budget. Remember to budget tips ($10 per person/day), excursions, shopping, additonal items like beverages, premium restaurants, spa, bingo, casino, art auction, shopping. Try alotting a dollar amount to all your miscellaneous things and back into the amount you can spend on a cabin rather than doing it the other way around. We are of the mind that we'd rather splurge on some expensive excursions (sea plane or helicopter tours for example) and take a nice inside cabin rather than a balcony.
BTW, it is my view that there is not much point in having an outside cabin unless you're going to have a balcony. Yes, it is nice to peek out and see the weather, where you are, etc. but in most (not all) outside cabins, the window is high enough that you can't sit in front of it and look out, you've got to stand up or kneel on your bed to peer out. Having said that, on my upcoming sailing on the Sun I have an outside cabin with a full length window but that's another story.
Now, I'm sure I've not given you any useful information but that's my story and I'm stickin' to it.