My old Airbus does not allow you to change the descent speed in the fms.The only way to fudge it is change the cost index until you get a speed approximating what is required.Once it is in the descent phase you can change the speed but this then screws up the path and you end up using speedbrakes to get the height off at Bexil.The whole profile descent in the fms becomes meaningless and you are back to vertical speed or level change.A direct to timba but be 150 abeam Bexil increase the workload as the fms does not generate abeams and the symbol generator of the efis cannot cope with the amount of waypoints in the South East of England and consequently hides Bexil on the ND!!A speed change again at Bexil further complicates the matter and the fms becomes just a navigation tool.Does the originator of this trial have a feel for the workload increase in the cockpit yet?