Originally Posted by pbarnette

It might be pleasant, but it might not end up being much of a mileage run, at least on DL. I would have to assume that, at that price, this is in "V" class, correct? Since the flight numbers are KL flight numbers, you will earn exactly ZERO miles with DL. If the flight numbers were NW flight numbers, then you would get full mileage + bonuses. Always book under the NW code, if you are offered the choice.

Luckily, at least for now, you can credit KL V fares to NW and receive full mileage (I believe they are the only ST program that still does this), but you will receive no bonus miles if you status is with DL. They should count toward status, but only when accounts are merged at the end of the year. You may also not be able to pre-book preferred seats (the exit rows on the A330 are very nice) if you put in an NW number, but you could try switching to the DL number, selecting seats, and then switching back closer to check-in and hope you can keep the seats.