SJS forgive me if I sound out of turn but if you were not married via a shidduch and married the only guy you ever dated then you cannot comment as you cannot imagine the emotions involved or the delicacy of the situation.
To date two people even for two days to use as a comparision is wrong. Your comment that the first few dates are more like an interview are also wrong. It has nothing to do with whether it worked out fine or not. Do you know the emotions felt by the person involved in double dating but was turned down after a comparison?
Some years back a child of ours went on a shidduch. Liked the person and wanted to meet again. After days of waiting and back and forth by the shadchan we were told the person had said no. We found out that they had double dated with our child who was mortified, humiliated and could not understand why they were being used and what was wrong with them and what was so much better with the other person. This child is now long married with their own family but still remembers this event. I therefore feel I can comment on this subject.
Double dating is wrong and the fact it carries on every day does not make it right.