Not sure .... I think I'd keep the inside.
We just had our first upgrade to a balcony (we always book inside). Those of you who said we'd be spoiled were right.
DH said next time (if the price were right) he'd actually spring for the balcony.
But as for bad location, that is a tough one. When we were offered the upgrade on FOTS, we had the choice of 7214 or 7216. We took 7214 (the most forward balcany). My rationale was that if we took 7216, and smokers took 7214, then we'd get their smoke. As it turned out, we took 7214 and the people who took 7216 were smokers. However with the forward action of the ship, it did not bother us, except when we were in port and they were out smoking.
We contemplated not taking the upgrade at all because the two cabins were forward. We were worried about rocking because my daughter has motion sickness. We didn't notice the rockign at all. I'd book 7214 again in a heartbeat.