Originally Posted by
andr0id
One point that has not been brought up, while you'll pay more for the electronic, you won't need to replace shift cables on a regular schedule with Di2. The most sad thing about the new 9000/6800/5800 mechanical is how the cable will get chewed up in the shifter becoming a SOB to extract. There have been several threads on here about that.
That's a significant factor to consider.
Consider with mechanical shifting or braking, you'll be tuning and/or replacing the cables more often (esp with new Shimano), but it's something that you can easily do at home.
With electronic shifting or hydraulic braking, you'll be doing less maintenance but it may require you to take it to the shop instead of doing it yourself.