Fiance (now wife) said her interview was very easy. She was asked only 5-7 questions. Interviewer did not even look at all the evidence she brought along. =) She was even a little disappointed that none of the 200+ pictures was not even looked at. But as many here have stated, it's better to have more evidence then not enough.
Personal note:
I believe that if your relationship is genuine and have enough evidence of support as well as the required proof/documentations, you will be approved. Overall, I think our K1 process was pretty smooth.
Consulate / USCIS Member Review #25839
Review on March 22, 2019:
