On the 8 domestic flights I've been on since 10/29, the NOS (when it has been operating) has only been used randomly, and less frequently at times when the security line gets longer. I have not yet been through an airport that required ALL pax entering security to go through the NOS, which would definitely take longer than usual. About 4 pax can get through the metal detector in the time it takes to body scan one pax through the NOS, from my observation.