If you dont get di2 your rather silly,its better.By along shot,and more future proof… and ergonomically more sound.The comparison between the two is massive.Im selling my Mechnical stuff after the national cyclo cross champs this weekend and then Im going electronic on all road and cross bikes.
Having run it on my dads cross bikes with no issues all year and me with dura ace 7900 on mine the and my road bikes.
hope thats useful,let me know if you have any more questions.