Eckhard - completley agree, 250 KTS is achievable, but from where we were it wasnt "instant" as we allowed the FMC to manage the transition in VNAV, hence my question above - if the controller wanted a more immediate response there are, as you know, other options that we could have used.
Re the 787 on short haul european work we are normally at higher levels (410+) and cruising at M84/85, it also descends on a much shallower profile than other Boeings I have flown ,so yes it is different- fitting us into the lower traffic in the descent seems to be a bit of a headache.