Hi Sarah,
Congratulations on getting DQd! You are nearly at the end of it all.
The interview went really well, it was very simple. In total it took about 2-3 hours since they first check the original documents you uploaded (marriage certificate and birth certificate) and if everything is okay you proceed to the interview. I was only asked a few questions about our marriage but in general very straight forward. At the end of the interview they tell you if the visa has been approved and you recieve your passport 7-10 days after.
As far as I know waiting time in Madrid is taking about 3 months after DQ to receive the interview appointment email but maybe this will speed up after the holiday season.
I wish you all the best!