It would be interesting to work out the cost of this exercise.Multiple AVAAs daily and days off in lieu for the volunteer staff,against retaining the ATSAs and a system which works.
I would be surprised if the break even is 20 years,just like some other wonderful cost cutting measures.
As for the system then the jury is still out on being fit for purpose.There are serious issues with it,that are safety critical.
As has been said before no doubt it will be brought in,with much trumpet blowing and fanfares.Until some poor sod has the first nasty because of it.The controller will no doubt take the can.