Haven't been to Narcoosee's in 10 years (and that time our meal and service was so horrendous, they comped the entire bill including beverages) but we love Flying Fish...most recently had a great dinner there sept 09. I am willing to try Narcoosee's again, though the reviews I see are definitely inconsistent.
Thinking not just about the food- what would appeal to your group more? fireworks view at narcoosees, or enjoying the boardwalk action before and after Flying Fish?