The Sinfonia is mercerized cotton, so it does have a bit more give than my experiences with Sugar 'n Cream albeit, not much more. I've never knitted socks with Sugar 'n Cream since I prefer sport or fingering weight for socks over worsted. I have trouble finding fingering weight yarn at my local chain retailers, though. I use 2s for fingering weight and right now I'm testing the sport weight Sinfonia on my 4s. Call me crazy (as most knitters experience a lot of "grip" with bamboo needles as opposed to aluminum), but I find that cotton plays much nicer with bamboo needles. I don't know why. You would think the stitches would glide off aluminum needles much easier.
Currently on the Sticks:
~Silver's Socks (3rd pair)
~Vintage style headband (my own design)