My interview took place in the US Embassy in Abu Dhabi on 1st march.
I arrived at 7.30am (Scheduled time 8.00am) and there were about 12-15 people already in a queue outside. Within 5 minutes they began to let people in. First step before entering is to go to a window as directed by the security guard where you will be asked for your appointment letter and passport. Once this is checked you enter the security area, Here you will hand over your phone and receive a ticket to collect it when you are finished. As noted by others no bags are allowed past this point.
From here you walk to the next building and are given a ticket number and asked to wait. I got number 613 (starting at 600). This series is for Immigrant visas. Shortly after Non-Immigrant visa applicants began arriving and got tickets starting at 300.
Everyone waits for there number to be called for the first step. There are display screens showing the number and the desk number to go to but the staff are very helpful and will manually call out the number if the person doesn't respond straight away.
At the first window, I was asked for my original Birth cert, marriage cert, medical report and also the Empost confirmation for delivery of the passport and visa packet pending a successful outcome. The lady spent about 5 minutes checking everything. She had in front of her the information I sent to the NVC. Once she was finished she directed me to the biometric (fingerprint) counter. Sometimes there is a short wait, in which case they will call your number.
After this I was told to sit and wait for my interview. After about 40 minutes my number was called. The CO was a man and he was friendly. Again he had all my documentation in front of him. I got asked a few questions. Where does my wife live, how long have I been in Dubai and where did I live before Dubai. All very straightforward. Then he said everything looks good, my visa will be processed and I should receive an email in 3-4 days regarding collection of my passport and visa packet.
I was finished shortly after 10am so just over two hours in total.
It can seems a little hectic inside at times as there are a lot of Non-Immigrant applicants coming and going but the staff are friendly and helpful.