FC on any airline isn't what it used to be. FWIW, Ive flown both and the edge goes to Delta. Don't worry about their Ch 11 filing....hell, every airline right now it seems is either in Ch 11 or on the brink. NWA's FC is an absolute sham. Its a larger cloth seat and you get a $7-12 type "meal" with your styrofoam cup full of coffee. Delta is respectable. Better seat, a bit better food/service, and IFE.

If you can, I'd shoot for Continental FC, which trumps DL and NWA But I know how hard it is to redeem on CO.

Good luck.