I have pretty much given up on Eco Pro - for the type of driving I do (mostly dual carriageways and country roads) the savings in Eco Pro are hardly worth it when weighed up against how 'unresponsive' it makes the throttle.
Most I have managed to save using Eco Pro for a tankful was about 10 miles (I typically get somewhere between 450-480 miles to a tank). That involved driving like a nun, avoiding braking as much as possible, leaving the A/C and other accessories off, etc. Nowhere near the 20% savings that BMW claim
If I were doing short journeys and town driving then maybe it would be different.