The train from station-to-station (CDG1 to Antony, near Orly) is about an hour. Add on 15 mins from Terminal 1 to the RER train station at CDG, and 15-20 minutes from Antony station to Orly (using the OrlyVal train which connects Antony with Orly's terminals). Luggage is a real hassle, due to lack of space on the trains and all the connections (shuttle, RER train, OrlyVal). Cost is about EUR 17.00.

The AF coaches can take as little as 50 minutes without traffic, but can take up to 2 hours during rush hour. This is terminal-to-terminal. Buses go every 30 mins on hour and half-hour, cost is EUR 15.50. Pick up at CDG terminal 1 is at door 34, arrivals level. Luggage is stored in the hold under the bus.

You can check out the following web sites for more info:

www.cars-airfrance.fr - click "lignes" then "3" - appears to be French only.
www.ratp.com - English option in upper left
http://www.adp.fr/webadp/a_cont01_an...100120123.html - recap of transfer options incl. taxi

I have done both and prefer the coach. You get on, sit down and can doze for an hour after the overnight flight. The train is crowded in the morning, you have to watch your bags at all times, and sitting idle in the crowd without being able to fall asleep is tough.

Regarding the policy of AF, I can tell you that they are normally pretty strict (i.e., use or lose it for discounted tickets) however if the whole thing is part of one reservation you have a better chance of being accomodated by AF and/or UA. UA has no reprensentation at Orly (I don't think there is any Star Alliance carrier there) which could be a problem if AF refers you back to them for reaccomodation.

Bon voyage!

[This message has been edited by PHLFlyer (edited 10-02-2003).]