My interview was set for 8.45, we arrived around 8am and entered within 15 minutes. We waited for a while inside before I was called to the first part of my interview, but that was on us for being super early.
Was asked a few basic questions, took about 10 mins. Told to sit back down and wait to be called by the consulate, called again in another 10 minutes, out the door less than 20 minutes later.
Super easy process going in and out! Only kind of weird that everyone can hear/see what's going on with your interview.