I am going to play the devil's advocate here and go against the flow. Stick with NW Platinum because out of the above mentioned airports and being retired and all, any other carrier will put you up in RJs or God forbid- SAAB twin props!

NW has a good partnership with KL and you can use your miles for RTW itineraries and all. Besides, look at your alternatives, if coming from unlimited standby upgrades, CO will not pay much attention to you and you will get less upgrades and always go through the EWRIAHCLE triangle. Plus they a much worse policy on international ugprade fares. DL, ha!, don't get me started there about upgrades and in the Midwest, you will have to put up with a lot of ComAir.

Among the choices left, AA and UA seem reasonable but if you are looking at 1K flying in and out of Chicago, forget about upgrades or preferred benefits!

AA is better as mentioned before but with exception of matching sale fares, their average prices are much higher than NW. Plus, either AA or UA has more direct flights and less routing possibilities.

------------------
"Fly me to the moon and let me earn alot of miles."