Thank you all.
Your comments mirror concerns I had: the size of the bag being small by US standards and expectedly a grossly inflated view of the insulation. I am also concerned about things like even (and adequate) fill and quality of construction.
I now have eliminated any thought of Chinese bags.
Anyone have experience with the Kelty Cosmic 20? They have overwhelmingly good reviews although a vocal minority have found cold spots and such issues. Seems like a good deal for $112. I expect their temperature rating to be a tad exaggerated, but when is that not the case?