Fuel surcharge. There are several threads on this site that discuss the validity of such charges. Another issue that is irritating is BA also increases the amount of miles required if your trip involves more than one airline. For example I finally sucked it up and booked a reward trip to Switzerland. It cost me 89K miles to fly in business on AA DTW-LGA then JFK-ZRH, however if I had wanted to fly DTW-MIA-MAD connecting to IB to ZRH, the mile requirement increased to 117K.

Personally I have had no issues with the AA Citi Card, not to mention that the AA Executive Card with Citi gets you Admirals club access and priority access if you are not elite ($450 membership fee for the Executive card I think).