On Feb 15, We fly rt IAD-VCE on AZ in C. Got to make a program commitment now.

I fly out of IAD/BWI mainly to Europe, in C.

SkyTeam airlines have far and away the best fares for this travel. $1800 to $2200 rt for most anywhere they fly. Will go to MOW in May for $2200 in C on AF.

Total mileage credit by then will be about 35-40k for the year with CO, less with most European partners, and would be orphan from the CO miles, which must be worth something.

Fly very little in US, so comp UG is not really a factor. Get lounge access with the tickets.

None of the European lines would issue a comp UG for my LH FTL.

Discovered wife & I had a total of 225k miles in CO. Called, and will get a silver elite(which immediately gives me 200% of miles flown) & they have a credit card of some kind.

Delta would probably also give silver. We have 110k there & they have a credit card. Think that is 175% of miles.

Is there an advantage to any one of the partners for me? Is there anything seriously wrong with CO? Or if there is, what about DL(bleeding money)?

Without any credit card, CO gives 50% bonus miles for silver while DL gives 25%. However, Song flights don't get mileage except with DL Skymiles, but since you said you don't fly much in the US, I guess that's not a worry. There's nothing terribly wrong with either CO or DL, but both aren't in a terrific shape either. DL is trying to do an image makeover with Simplifares and route network redeployments right now, hopefully that'll help boost the bottom line. I don't think any of the business matters directly impact your FF programs though.

Personally I like DL but that's because of my MCO/BOS location. I guess it really is up to you to choose a program. I'm sure others will chime in with their respective opinions as well.

If you strictly choose only between CO and DL, I will choose DL. DL-AMEX Platinum credit card is GREAT with extra 10K MQMs miles each year after spending 25K and 10-12.5K miles after first purchase ona new account plus 5K MQMs mile upfront. If you plan to achieve 75K MQMs miles to get a Platinum Status (or already is one), then, "only in my opinion," DL is a way to go because you will get CRC Membership and 6 Upgrade Coupons (although I know you fly mostly on C and lounge access is not an issue to you, but upgrade coupons can become quite handy some times for you or your travelling companions) when you pay only Y, B or M (Economy Full Fare).

However, if you plan to fly CO/NW a lot within the next 12 months, then go for CO because CO and NW are 100% compatible to each other while DL still kind of not really completely migrates into CO and NW regulations and benefits as of yet (vice versa). Once all 3 are fully together, then I don't think it matters much which program you are in. CO credit cards suck, in my opinion, less bonus and no elite qualifying miles given.

If you plan to achieve MILLION miles, then CO or NW does not recognize Million Miler Status as of yet, DL does.

Hope this is helpful somehow.

From what I found on the Delta site, MQM miles are status credit miles.

I cannot find anywhere on the Delta site, the AMEX site, or in the Delta forum that the AMEX miles are MQM miles.