The Global Entry interview took all but 10 minutes.

We used the Global Entry line in Customs because we thought that was where we were supposed to go. That saved us a lot of time in the customs area. That customs agent told us to retrieve our luggage and go into the customs office which is located right within the luggage area. The agent that does the "interview" was on his dinner break. After a few minutes, he saw us waiting and came over and took our passports. After another few minutes we went into his office. He confirmed some information and we were on our way. There was no one else waiting for the interview so for us it was probably 20 minutes altogether.