In the 70's I travelled the MAN-CPH route every other week for just over 6 months.
The choice of carriers were BA with 732's and later 1-11 500's, EI with 1-11 200's and SK with DC9 300's. My personal preference was the EI flight purely due to their superior catering. The EI and SK flights originated in DUB whilst the BA flight was MAN based.
Most strangely both EI and SK pulled off the route at the same time although SK later returned. This cannot have been because they were losing shedloads of money as all three services were well patronised and the airfares were not exactly cheap on this business biased service.