I suppose this is directed more at Andrew and maybe Jay.

I just spent 45 minutes replacing a front derailleur shift cable and tuning the front derailleur to operate silently.

How much faster do pro mechanics do to achieve the silent running that usually takes me so long? I say this because one of the largest features of Di2 is that a single rather rough adjustment of the Di2 allows the front and rear derailleurs to run smoothly and silently with fully automatic trimming of front as you shift.

Surely there is a reason that Shimano went to so much trouble to include all of this complexity.