Campagnolo

Comprised mainly of a mechanical structure, the movement of the derailleur is via an electronically-actuated worm gear and motor with resolver & sensor
The parallelogram has been made more rigid and optimized to accommodate the electronics
A resolver reads the movement of the derailleur and optimizes its position, and a play recovery system that maintains stability over time and many kilometers
Mechanical limit adjustment screws and end stop are included, just like a normal derailleur
Can be shifted over the entire range of 11 cogs in 1.5 seconds
Has both a Zero and riding setting; requires being set on two sprockets during setup
Uncoupling feature prevents damage to the actuator during a crash or other severe shock and allows the manual selection of your preferred gear if the battery is exhausted during a ride