Chorus of joy.
The Campagnolo Chorus 11 Front Derailleur may be the biggest beneficiary of the group's redesign for 2015. The new cable pull ratio in the Chorus shifters means that it enjoys an extra position of trim while in the small ring, so you can actually use all 22 gear combinations in your drivetrain with no chain rubbing. That fact alone is enough to inspire us to break out in joyful song, but the new derailleur has a few other improvements that make the deal even sweeter.
For 2015, the derailleur gets a longer cage for greater leverage, so less force is required to effect an upshift. The cage is also narrower, so you can exert more precise control over shifts. The metal cage is built to stress silent shifting without sacrificing Campagnolo's legendary snappiness. The derailleur also includes an optional cable deviator insert. With some internally routed frames, the front shifting cable comes out so close to the derailleur that it can rub against it. The deviator insert prevents this.
The Campagnolo Chorus 11 Front Derailleur is only compatible with 2015 Campagnolo Super Record, Record, and Chorus drivetrains. Compatibility can be determined by matching the letter on the bike side of the inside arm with the corresponding markings on your other drivetrain components.