I just finished this scarf on Saturday too!
Mine was in Crystal Palace Musique in the Lagoon colorway (greens, blues, and a little purple).
I used size 9 needles and cast on 26 stitches. Musique is a thick/thin yarn and the effect was great! It ended up being about 6 1/2 inches wide, and I made it 60 inches long. Looks great from both sides!
I also made a slightly modified version of Marnie's Nautilus hat to go with it, and they're for my 16 yo niece for Xmas.
(I know, pictures. Still working on the camera angle - Xmas present (fingers crossed)!)
Happy Knitting :XX: :XX: