In my early days of bping, all I ever had was a Sears, synthetic fill bag that my folks got me when I was a young kid, mine I believe was five pounds. It took years before I could afford a down bag from Campmor. Loved it. Something important like a sb, I have inside my pack, unless it is a five pound sb, in which case, if it was strapped on the outside, you'd notice if it fell off. I once saw someone with their down bag strapped on the outside with one strap, about to fall off. Not sure if they made it home with it. Enjoy the new lightness. Now, I like the old bags as they are more comfortable when car camping.
Duane