For the first time in ages I heard of someone the other day flying BA, LHR-EDI and, as so often was the case, the luggage went missing.
I don't know if it is BA or LHR that is to blame but I would not go NCL-LHR with BA if there was an onward connection. I might if I loads of time to retrieve it at LHR or, best of all, take the train.
AMS seem to have totally sorted their problems out.