OK, so here is the deal
Our interview date was for 9 AM, we arrived to the Embassy around 8:15.
You can only enter through security and the guard told us that we can only be allowed in max 15 minutes before our interview time, so we had to take a walk around, and come back at 8:45.
We arrived back on time, we were put through security by twos, first the girls, then the boys. You are going through security like in an airport security, but you have to leave every electronic device behind (phones, car keys etc.).
You are let into the main waiting lobby, which looks like a bank lobby, with electronic numbering system and windows with numbers. You have to take a number from the ticketing device, then wait for your number to appear. We sat down and waited, it was a bit funny, because we were the only ones, only one other visitor to be seen during the whole process.
After 5-10 minutes, our number was shown, and we had to go to a window, where they were asking for all our documents, passports, birth certificates, police papers, bank statements, affidavit of support, and only my grammar school diploma (no college diploma was asked, nor anything from my wife). They collected all the documents, and made copies of some of them (only remember the police papers). They took the fingerprints from the adults. They asked if we have an address to send eventually the green card, so I wrote the address on the paper that was originally sent to the KCC. They asked if we know some basic facts about the DV visa (they can't refund the fee, we have to leave for the US in 6 months etc. everything we knew, except that they told, that if we want, and needed, they can postpone the issuance of visa by some time (wasn't specified), but we didn't ask for this possibility). They explained that we will be called to another window to pay the fee, so we should again sit down and wait. After waiting some, our number was called again, so I went and paid the 1320 dollars. The cashier was quite chatty, she asked if we go as a family, how many times we played the lottery (wow, win for first time), where do we plan to settle (wow, I am from California too), this was all unofficial. Then I got the receipt for the money, but were told that the official receipt will be given by the consular, who will call us next, until then, sit down and wait.
After some time, we were called to another window, where the consular was waiting.
The interview was in English. I spoke, my wife was only asked once, I helped with some interpreting.
She asked us to sign the papers that we sent to KCC (what you are not supposed to sign, when you send), that you are not a terrorist, child trafficker blah, blah, blah. The parents signed for the kids. Then we were asked to take scan our fingertips again, adults only. This was for the criminal records, I believe. Then we were asked to raise our hands and swear that everything we submitted is true.
The interview was the following (not sure of the order, can't remember exactly):
Q: - The person who gave the affidavit of support is your cousin, right?
A: - Yes.
Q: - When did you last meet her?
A: - In 2011, blah, blah, blah.
Q: - Is she a US citizen?
A: - Yes.
Q: - How did she become a US citizen?
A: - Answered what I remembered.
Q: - (this question I just remembered) Have you any other relatives who live in the US?
A: - Answer.
Q: - Have you been to the US?
A: - No.
Q: - Then, why do you want to immigrate?
A: - Answered why.
Q: - What do you do for a living here?
A: - Blah, blah, blah.
Q: - How much do you earn a year here?
A: - Blah, blah, blah.
Q: - What company are you working for?
A: - Answer.
Q: - What do you plan to work in the US?
A: - Answer blah, blah, blah.
Q: - Where do you plan to work (geographically)?
A: - Answer.
Q: - Does your company you are planning to work for has an office in the town you plan to live?
A: - Blah, blah, blah.
Q: - If no office, how do you plan to achieve this?
A: - Blah, blah, blah.
Q: - How much money are you planning to bring to the US?
A: - Blah, blah, blah.
Q: - (To my wife) : Madam, what are you planning to do in the US?
A: - Answer.
Q: - Do your kids speak English?
A: - Answer.
Q: - If you get the visa, when do you plan to move to the US?
A: - Answer.
Q: - Do you have a house in Hungary?
A: - Answer.
Q: - Do you plan to sell your house?
A: - Answer.
At last: Congratulations, hereby I approve your application for the visa.
Then she gave us the receipt for the money we paid.
She said to wait for another call to the first window, where we get back our documents, and further instructions.
The whole process didn't take more than 10 minutes.
Then we waited again, now happily.
We were called again to the first window, where we got back our birth certificates and my grammar school diploma, and were explained that we will get back our passports in 1-2 days, they asked for a telephone number to notify. I asked if we have to pick up the passports ourselves in the Embassy, and they answered yes. They also gave a small piece of paper with availability of the Embassy.
Then I couldn't ask more question, because the fire alarm went off!
We had to leave urgently, the guard asked us so.
So we promptly left for the security post, where we got our pieces of hardware back and could leave.
The whole process took only about 1 hour and 15 minutes.
OK, maybe I forgot something, but in a nutshell, that was all.
All in all, everybody was very kind and very helpful, the process was efficient.
Hope you will have the same great experience.
Good luck to you all!
Any questions? Post them.