I think that's more in keeping what I need to know. I use a Monbell UL #3 spiral bag (30 degree) that I use more as a quilt than anything. I want to sleep in something light, while protecting my bag. And if it's hot, the silk might be nice against me instead of wearing running shorts.
David...I agree about the wool. I wear merino whenever I can, but the weight of silk and a good price is what I am looking for.