Thanks all
I didn't want to start the Yank Vs Frog argument up, but I do have to say as a controller the Boeing aircraft do get up quicker as a rule which helps us out. A340's (especially when flown by Cathay) climb like dogs, due to them doing a cruise climb.
I think Airbus's were designed by beancounters, while Boeing aircraft were designed flying enthusiasts. Anyway that wasn't my topic.
The thing is that even though the IAS may stay high on the A330, cos they descend so early you end up with the A330 10,000 ft lower than the guy 10NM behind in trail thus much slower in ground speed which is what counts for us when running a sequence. So invariably the 767/747 has to be pulled back to 250kts to stay behind the A330 doing 300ktIAS. Thats the problem we're left with. And with Emirates buying A330's by the bucket load its getting to be a pain.