That's as thin as Thermore, which is the only poly batting I've ever used.
It worked fine for a throw I made my Grandmother, where I didn't want it to be to heavy on her legs. It works fine if that's the effect you want. Also, I know it's often used for clothing, as it drapes very well.
But, heck, if you've got 100 yards, you could easily double it if you wanted more warmth. It still wouldn't be "heavy."