A couple years ago, I was entering at ORD from Germany when they had a big mess, with four to six hour lines, Fortunately for me, the GE kiosks were working, and I got through instantly, although it seemed funny to walk past long lines of people who had been sitting in the hallways for hours.

I also experienced an CBP meltdown at DTW when I was on a late flight from Asia. They set up a makeshift fast track system for those with tight connections. However, DL didn't handle this very well: their long GA welcome speech omitted the most important information, namely that the CBP computers were all down, including GE, and even the person doing the fast track triage seemed unaware that the GE kiosks were also dead. It was also frustrating that crew from the previous flight were in the fast track lane, which might have caused some paying passengers to miiss their connections; arriving uniformed long haul international crew would not have been assigned to work flights the same day and IMO should have given priority to customers, including elites who had paid for premium cabin tickets.