It is interesting that it mentions our 2.0 Duratec DI. I find this part of the article particularly interesting:
Stephen Russ, technical leader for combustion for Ford’s 2-liter Duratec DI engine, said that similar to GM, engineers have determined the proper injection-timing calibration to help eliminate the carbon deposits. But Russ also said the technology of injection components – particularly the high-pressure solenoid injectors – has quickly matured, meaning excess valve deposits in most DI engines should become a thing of the past as these improved components are incorporated into production.
That highlighted part makes Stephen Russ sound like he's not quite sure, doesn't it?