Recently booked ANC - ATH//IST - DCA on DL. Thanks to this forum, avoided the DL operated as KLM/AF like the plague. Managed to find all DL/AS metal in DL T class for the dates I needed. Also nice that I am connecting ANC - DCA - ATH on the outbound with one AS flight and the rest on DL, so I anticipate the double RDM bonus, which will be significant!

I agree with other frustrated posters above that the partner codeshare issue is annoying. However, KL/AF discounted Y fares are not eligible for earning anyway which makes me lean towards DL in most cases. KL and AF both published similarly discounted DCA - IST fares, but only DL's fare was eligible (T class).

As an aside...interesting to note that DL coded AS operated flights also fall outside the MP earning ranges, but I have always had these post (usually manually).