As a NYC based flyer, it would depend on what your travel patterns look like. CO does not fly to LHR, although partner VS does. I prefer CO-hub EWR in NYC because of the easy train to Penn Station.
For what it is worth, CO seems more oriented towards value for customers with an all-inclusive pacakge (i.e. blankets, meals at mealtime, no incremental charge for movies, included wifi and booze with lounge membership, etc) and AA seems focused on trying to get a cost structure below WN with charges for blankets, meals, movies and surcharges for wifi and booze in the lounge.
Finally, I'm a little taller than average and have no complaints about the CO pitch.