Had our K-1/K-2 (for my 2 children) interview yesterday. In general experience was good: local staff who was preparing our package (this is a step before the interview) was extremely good and helped us. I didn't have my fiance's divorce certificate (they request to have an original) but he still decided to pass it on to consul (he could have just sent us home). I am veeeeery greatful to him.
The interview was very short - how and when we met for the first time and when and where we met after that. That was easy
In total it took 4 hours: arrived at 7:30 (appointment at 8) and left at 11:30. interview itself was around 11 and took 5 minutes