Don't know much about that part of I-95, but when I lived in DC, I would much prefer the USAirways Shuttle to driving I-95 to New York. Based on the location of the airports, however, I would never have flown BWI
to get to New York.
Here in Austin, my general rule is that if I can get a r/t ticket to Dallas for less than $90, I will probably fly. If I'm visiting friends in Collin County, Arlington, Grapevine or Ft. Worth, I'll take AA
. If I'm visiting friends in Dallas proper, I'll take WN
I know that probably doesn't help with your Florida question, but that's my general rule.