Finally got around using it the first time at SFO. 2 kiosks, saw 1 person just walking away when I came. No line at all, done in about 2 minutes on the kiosk. Had only carry on but had to wait around 5 minutes in line to get out of the customs area.
Adding up all including walking it took me around 15 minutes from leaving the plane to a shower in the arrivals lounge.
Very nice and definitely worth the money.