Spekesoftly has it about right - do precisely what ATC says and you're covered. IMHO there is alot of confusion these days between controllers and crews because many ATC procedures are stubbornly stuck in the 1960's and haven't caught up with the advances in the cockpit. I bet there are a fair few controllers who don't know when or where a modern jet will be flying headings, and when track. We have problems with A320's announcing they will fly an approach using 'track', but SRG insist we say 'heading'. Likewise our approach plates give the SRA glidepath as 2.8 degrees, but we have to tell pilots to descend for a three degree glidepath. Just like the old days of Meteors and Vampires! Modern flight decks enable aircraft to be flown incredibly accurately - it's about time ATC caught up.