One extra benefit, that everyone seems to overlook, is that with the advent of 11 speed, now all 3 group's drivetrains are compatible with each other once again. During the 10 speed days, you were stuck to some degree. Not any more.

Meaning, you can use any Sram/Shimano/Campy 11 speed shifter with any Sram/Shimano/Sram 11 speed rear wheel.

So, if one day you should get a good deal on a campy 11 speed wheel, or decide to change to Campy 11 speed shifters & rear mech, it will all still work as a mix n' match.

Note: I am not 100% sure about 2015+ Campy shifters / rear mech. They redesigned everything starting there.

Sources:

1) Myself using 2014 Campy Record 11 speed shifters/mech + Sram 11 speed cogset.
2) Leonard Zinn
Drivetrain compatibility hidden in plain sight - VeloNews.com

IMO, this alone is 99% enough reason to go to 11 speed over 10 given the choice, assuming the cost is close.