My interview was scheduled for 9:00 am and My fiancee and I got there around 8:40. We parked in a parking lot near by for 250 pesos. We noticed a conglomeration of people in a street nearby the embassy (Im not sure what was the deal with that)... We ignored all the buscones and proceed to walk to the consulate building. I asked the guachi where is the line for K1s and he pointed at the shortest line.. I stupidly forgot the appointment page so we had to go back to the buscones area and pay 300 pesos for them to print one page (luckily I have all my info on the cloud so it was easy to login into my account and hit print).. We got in, passed security and were assigned a number. We were called into a first window where we handed in the documents we brought (police certificate, birth certificate BRING A COPY OF THIS ONE, etc) I was handed back the affidavit form and documents and told that that is not required for K1s... He also asked me if I had a 2x2 photo because the one on the system wouldnt load.. So I would say be prepared for anything, bring copies of everything just in case... After a LONG wait (there were only 2 more couples in the building by this time) we were called into another window... the interview was in english since my fiance doesnt speak spanish.. they asked him how me met, and they asked me a couple of questions about the student visa I previously had.... after that he said you have been approved and we left the building!! it was 1:15 when we got out.
I did notice that people that were alone without the petitioner had longer interviews and were asked LOTS of questions.. but still got approved