3 things important to me regarding FC not already mentioned here:
1) No standing on the jetway waiting on line. Board early, at leisure. (I usually get this anyway for being elite.)
2) Reserved luggage space for when you board late and all the coach luggage space is filled.
3) 1st off the plane when you have to run the 1500 meter dash across IAH, DFW, DIA, etc. to make your connection.