Thanks so much for your detailed reply.

Looking from where I am right now (flying out of TUP/MEM), my original thought wasn't to actually fly on CO metal (other than intl), but to fly on NW metal and use my CO as my FF number -- since CO and NW elites get equivalent service flying on each other's planes domestically.

After testing a few tickets on co.com, I realize that if I do this, I will be unable to do this easily, and thus will lose out on the bonuses provided by co.com

That being said, I'll have to take a close look because Q (or better) is usually what I fly anyway, so the 50% penalty for booking through expedia or NWA may not be an issue...

rubindj