One advantage of Shimano’s Di2 is less wires and cables. There are still a few wires which need to be routed cleanly and properly to take advantage of the system. Images here show a clean installation. Take the time to tape or zip tie in temporary position before permanently routing/installing. The extra time spend is very rewarding. Less flapping ore exposed cables/wires means less air disturbance… more aero. Riding a clean looking bike gives me confidence and pleasure.