I can comment on an Alpine Design 20* mummy bag, bought at Sports Authority. http://www.sportsauthority.com/produ...rigkw=11028492
Outer shell: decent.
Durability: terrible. 1st use/2 nights- developed a long rip internally along the seam. I sewed it back up. 2nd use: new rips developed, my repair held, but the seam tore past both ends of my repair.
I'm not sure what weight material A.D. is using inside their bags, but the sewing is not good. I'd spend a bit more money on a better-rated bag.