TDM,
To be fair, Thames/Heathrow normally provide a superb service to Heathrow SVFR, City VFR/SVFR and to IFR inbounds and outbounds. Really superb. That is what I said in the first post.
As I understand things, they are going through a difficult patch at the moment with SERA and LHR Class D retraining.
However, they do have a duty to maintain the service they are contracted to provide, and (and this is the important bit) we in the GA community must resist any de facto slipping of Class D VFR provision.
I have raised two other places where there are concerns, Farnborough and Solent. This is as much about precedent as anything else.