Need your advice on yarns!

Hi! I have not posted because I am not knitting Picovoli yet (oh...). I have promised myself I will only start a new project when I finish the 2 sock pairs I have in progress, and then it will be Picovoli, of course.

I checked my stash, and there are 2 yarns in there which seem nice for this pattern (I have enough yardage of both). One is 100% non-mercerized and soft cotton. (The true colour is more interesting, the light pink is a complex, warm light pink, and not a bluish as it seems in the picture, and the blue is a bit darker). It is matte and not "ropy" at all. The other one is a 50% viscose 50% acrylic mix, shiny/satiny, in a dark wine colour (I will take a picture some day, it's more or less this colour, maybe a bit darker, but more satiny):


So, I need the advice of those who have already knitted or are knitting Picovoli. Has someone knitted it with a 100% cotton yarn? Are you happy with it? Did it grow after being knitted? Is it a good idea to knit it with more negative ease than usual? What about a viscose mix yarn? Has someone knitted Picovoli with it? Are you happy? Does it grow? What general advice do you have?

And finally, a poll: which of the 2 yarns is best for a Picovoli?

Thanks!