They seem to be quite good.
Singapore has 8 seats each way per day, and on average there are between 2 and 4 booked, but it is helped by Munich which helps fill that cabin. What is interesting to note, that over the past few weeks, MAN has pretty much filled the B77W on the outbounds, leaving about 10 seats for Munich passengers. Not bad.
Emirates does very well, bear in mind there is no destination to split with. It offers 30 seats per day each way, and there are many days the EK18 and 20 is full, so we know right off there that all F seats are sold.
It will be interesting to see how Saudia do. They will do well on cargo, as they often send B747F's into MAN. The loads were ok last time around, but, they switched their European strategy to use A320's which were useless for cargo and also unable to reach MAN with a decent load. The fact MAN is now one of their few European B777 routes shows they are expecting good things.