I flew home last Sunday afternoon (4/14). It took only 16 minutes from the curb to the duty-free area. I took a break for a beverage or two and a couple of cigarettes in the bar area there. When I resumed my journey through the airport, it took 15 minutes to get from the duty-free area to the gate.
I was expecting much worse than the just over 30 minutes it took for the whole process. I didn't count how many US customs personnel were working, but the wait there was less than 5 minutes.