Last week I needed to book JFK-AMS-JFK for my wife to rendezvous with me for Easter in Amsterdam. The AA/BA codeshare through LHR was $1,400- no go. The nonstop flight on Delta was $1,100 on Delta.com, but $640 on AA.com! Needless to say, i snapped up the AA.com booking, and double confirmed it with Delta customer service. Thanks AA.com!