jaded boiler A good question. I asked a similar question of Dick a few pages back and did not receive a reply. He appears to have gone quiet.
What is the BIG advantage of E of D rather than C over D? What is the difference in cost? Where is the analysis?
Without KNOWING these things we are just talking in circles.
The buying a car analogy is useful, follow it through, would you buy either car without being told the price first, whilst STILL making the decision which one to buy?