Pros
EXP Line A+
EVip Program A++ (puts DL to shame)
EXP (Emerald) Global OW F Lounge Access A+
Reward Redemption B (better than others, but one needs to be flexible; BA offers GGL level one any seat available redemption per year)
Cons
The Airline C (once known for clean, new planes and leading edge products - think International Flagship Service in the 90s), the actual in air product is bottom middle of the pack among domestic legacy carriers IMHO. NGBC was dated from the day it was introduced. Continued management - labor issues have taken its toll on service.
Overall - B+ (AAdvantage is a great program particularly if you can make EXP and want to fly up front on low fares; also if the AA network works )