We had our interview on December 7 in San Diego (I485 AOS). We waited for about 30 minutes after our scheduled time and our interview lasted just under 30 minutes. Officer was very kind - to the point - but he did engage with us and we had some laughs.
Questions were pretty basic - nothing surprising or out of the ordinary or too personal at all. It really was easy.
When it came to photos, we had put together a little 'chatbooks' photo album (check out the app - it's brilliant). He loved it - flipped through every photo of the 60. Asked a few questions about a few of the photos, then took some copies - and handed us our approval notice
Green card arrived one week later (it REALLY is green! haha).