It's still not my favorite dress, but I picked up some interesting tidbits from the SVT documentary on royal wedding dresses.
Fair warning: the video is in Swedish and while I was able to get English sub-titles, there's a chance that something got lost in translation.
Silvia said that she when they were planning the wedding, she went to spend a weekend in Copenhagen as the guest of Queen Ingrid. There, they looked over dress sketches together and picking out the Christian Dior dress that she ultimately wore.
What really blew my mind, though, is that they used the train from Princess Birgitta's dress instead of the one originally supplied by Dior. Silvia wanted something from Märtaskolan since they made the dresses worn by Carl Gustaf's sisters, but the dressmaker had closed permanently a year before. So Silvia had the train from Birgitta's dress (also worn by Princess Desiree) added onto her gown. I still don't like the gown, but the sentimental gesture of using the train softens my dislike a bit. Can you imagine what she would have been able to wear if Märtaskolan had made her dress?