DFW and MIA are simple because AA is the dominant carrier. ORD is a more difficult call. Do you put the club:
- In an AA concourse;
- In a UA concourse;
- Outside security as at LGA;
- Or do you build two reduced service facilities (see SEA)?
This assumes space is available. American Express cannot build just because they would like to, there needs to be a vacancy, and they need to be the high bidder (or negotiate a no-bid contract as they did in Miami.)
ORD could be fine in any concourse, as it's relatively easy to connect inside. Sure, it's a walk, but it beats the pants off having to re-clear security. I think T3 makes the most sense, but I'd imagine it just has to go wherever there's space.