Very simple, interviewer was very nice. Just make sure to bring everything and arrive about an hour early. I was done in about 45 minutes, I was booked for an 8:30am and there was a lineup of about 25 people waiting outside before they opened the doors, most of them were going for a K-3 Visa though.
Also do not bring any backpacks or purses with you, they will tell you to find somewhere else to store it as there is no storage there for personal items.