I can tell you that I have a Big Agnus Insulated Air Core Ultra.
The heat loss to ground at 20 degrees was significant. If it was any colder, I would have needed a foam pad as well to add to the R value. Probably ok for archery season, but I would not use it for rifle season.
What do you consider better?
Higher R value
Knowing that will help narrow down the choices[/QUOTE
Basically if there is any other decent options in this size. I havnt been able to find any