Another data point - my fiancé & myself had our global entry interviews yesterday in Pittsburgh. Interview literally lasted about 5 minutes. Only questions I was asked was 'whats your interview time; whats your name; and is your address XXX'. Took my pic and fingerprints and was out of there. Same with my fiancé.
I'd also add that we happened to arrive about an hour before our scheduled time but they took us then anyways.

Only got a small slip of paper showing how to use the machines, no video or anything.