Very quick and easy process. Was made to feel at ease and everyone was very polite (except for the English lady in reception before you go to the lifts :/ ).
I was asked for:
1) One US style passportphoto
2) Birth Certificate
3) ARCO Police certificate
4) Passport
5) DS-160 confirmation page (you have to provide this to get into the embassy)
6) Affidavit and tax returns - I didn't think was needed and only had W2's, they said this was fine and it wasn't a huge concern for K1 VISA applicants anyway
He took my fingerprints and then I waited for the interview part.
I waited about 10 minutes and all I had to do was take n oath to say everything I said was the truth, She asked how we met, and where I'll be living (house or apartment). She then casually said well we will issue your VISA once your medical arrives.
My passport had slight water damage to some of the pages but this did not seem to cause an issue.