None of the airline alliances are truly seamless.

Despite its headstart on oneworld and skyteam, Star Alliance, for example, still does not have an integrated reservations system. Oneworld, in fact, has achieved better systems integration than Star Alliance because of the connections that AA maintains with Sabre. The Sabre people figured out how to patch all the oneworld systems together before Star Alliance even had a plan for their own system's patch.

Oneworld does some basic things quite well:

Lounge Access based on FF level with EXP's getting First Class Lounge Access, Plat's Business Class Lounge, and even Gold's regular club access.

Award redemption: With oneworld awards, one does not need separate awards to travel on more than one oneworld carrier. To many destinations, oneworld awards require less miles than two separate awards, as it the case with most of the other alliances.

Quality of Carriers: AA's has partnered with some of the best carriers in the world. Almost all offer a suite product in first class. Their club facilities are among the best and most prestigious in the world, for example, Cathay's Wing Club in Hong Kong.

Elite Qualifying and Bonus miles: Can be earned on all oneworld carriers.

To be sure, AA works better with some of its partners than others. For example, AA's working relationship with Qantas is much better than its working relationship with BA. But, each partner recognizes and acknowleges on average the elite FF's of the other. I have no problem, for instance, getting into a BA Terrace Club or even First Lounge with my EXP card.

The only thing that is holding oneworld back is the inabiity of AA and BA to codeshare or to coordinate schedules. It would make some connections at Heathrow easier if they could. However, even if they can't, I am not going to start flying through CDG. In my opinion, I would rather tolerate a two to three hour layover and slightly higher fare than AirFrance.