It is strange that some respect speed instructions less than HDG's etc. I thought it was cultural but it seems there is more to it. I'll start spreading the word over here that ATC is watching IAS. We'll see if that scares them into compliance.
Hahah
More common than you would believe. A certain south european airline seems to possess a cultural quirk among its pilots where ATC speed instructions are regarded as something of an advisory thing..kind of yeah yeah reducing to 240 indicated, I know what I'm doing, 260 it is until he asks again. I was present in a discussion recently when the downlink of FCU parameters was discussed in the presence of a small number of representatives of said culture and the red faces were almost visible.
As said earlier, London TC have been operationally using these so called Mode S EHS elements for at least five years now. Elsewhere in the Eurolands the idea has been toyed with here and there and it is my understanding that the latest ATC system offering out of Thales will support it and it will be up to local ATC providers to enable/disable what they find useful.