BillyBob, Thank you for your reply.
I meant to post this in the general "bottom insulation" forum rather than the specific Pads.
In reading posts, it seem many have had both HH and WB at one time and wondered if they found the two different insulation styles different. The WB has that interior sleeve and the HH has the undercover.
I was also puzzled about the cold strip, but I was too comfortable to move
I know the bag wasn't always completely under me - I started out using it as a quilt. But maybe things did shift around a bit. I got into it in the dark and it was a bit chilly at the time so I was "under the covers" in no time.
Anyway - it was fun to wake up to snow and have no pressure points on shoulders and hips - as happens with ground sleeping.
This was the Blackbird model. I haven't tried the ridge runner yet.