I agree with PCad. At some point Di3 or 4 will compute big ring and small ring shifts, even measuring data from a power meter, you set some parameters, and then the electronic brain takes over. This will eventually evolve to manual vs. automatic transmission for bikes. I'm an old-school guy. I drive an automatic transmission in my SUV today (5 speed + Lo/Hi 4WD) , but my fondest memories are driving stick shifts, and for 4WD, having to get out and manually lock the front hubs, sometimes in rain and mud. It was fun adventure, like going into Baja and unmarked "roads", pre-GPS and saying, "I can get us there, I'm really good at map-reading and dead-reckoning." And I was reallly good at that. And often really scared. But I didn't let my passengers know the latter. Cuz then they would just have hounded me to turn back. What kinda fun is that? It was waay more fun to deliver them to cool places.

I got Red before it swept the TdF podium. I liked before and aI like it afterwards. If Di2 sweeps this year, I'm not changing...not right away. I stuck with manual transmissions for my MVs for a long time.