I'm a UA fan myself, but I'm afraid I may have to concede to AA on MCI. On a scheduling basis alone, American just offers more flexibility than United does.

For example, on a recent trip I booked to MCI, American's last two departures from ORD were at 8:32pm and 10:18pm. United's last departure was only 8:05pm.

Same thing going back to ORD; American's last departure is at 7:09pm, United's last departure is only 5:50pm. To me this is more of a problem, since it means cutting meetings short to ensure I get to the airport on time, or else I have to stay an extra night.

I haven't looked into DEN-MCI or DFW-MCI to see how they compare.