Airbrake, I would not know exactly but I would bet 250Kias.
I was stitched this morning, an aircraft decided to fly 180Kias from approximately 20-25 track miles from touchdown. This incured a penalty to me (no.2 behind) and the four aircraft behind in the sequence.
My point is nothing to do with which CI or which speed is best but airmanship/professionalism. When someone is flying slower it will inevitably cause a bottleneck and result in a fuel penalty. (I could not care less about the 1 or 2 minutes extra flying time)
I try and keep the thrust levers closed from TOD to four miles as much as possible - this in my opinion burns the least amount of fuel. I dont roar around at 320Kias + and I do ok.
For the sake of argument and this thread if Ezy want to plan for a slower descent, no problem