Giles Wembley-Hogg, I didn't say the use of the word Heading was overkill, I believe that the word degrees after saying turn left heading 270 is. In the Middle East, I would most certainly talk to more US military pilots than you would in the UK, and honestly right now, probably as many as the domestic American controllers do. They are everywhere over here as you can guess.
I have had not one instant of confusion with them due to not saying degrees or hectopascals or millibars after the QNH. I have had a lot that have just done what they want in complete contravention of the clearance they received, and even more whos ears are painted on, but the phraseology and the differences from different controllers from all round the world has not caused problems.
Generally I have found the American controllers (US and Canadian) are the briefest with RT, and the UK controllers at the other extreme, saying a million things that many other would find unneccesary all to tin plate their arse a million times over. I think the Aussies, Swedes, Sth Africans etc. over here all fall somewhere in the middle ground. I guess whatever works for someone is fine, but I would have aproblem if in a check I got chipped for not saying "degrees", or "millibars" etc. I won't though cos thankfully it's not in the books here that we have to say it.