GlobalEntry is worth every penny. It truly does pay for itself. The next time you are at ORD standing in line behind hundreds of people at passport control, think of how easier it would be to zip through by using the kiosk!
(Plus, even if the kiosks are not working, you can skip to the front of the line and/or use the crew line.)
PLEASE sign up! The more members in the system, the greater the incentive for CBP to deploy the kiosks at more airports.