bigiron...
i can obviously only comment on the type of airspace i control...yes in europe the UK to be exact. when sequencing and spacing aircraft speed control is very important. we generally use three speeds for which they are known the last being 160kts to 4dme. if a pilot chooses without infroming us to reduce to 160 what happens to the aircraft 3nm behind thats still at 180 kts? the answer normally is that aircraft doing 180 kts gets broken off the appraoch, costing more fuel and time to that operator.....is that fair?