Dustin, just asking for others' experiences, don't know if the mattress was over rated.
Roger, thank you for the informative answer and some of my thoughts too, really appreciate that.
The CA group I have done many winter and summer trips the last 9 years, we've never discussed mattresses much if at all, but then, not everyone goes out in these temps. Our group without me has done sub-zero trips, mine have all been solo trips, relying on my old snowmobile to get me back in there, usually in the Perazzo Meadow area off of Hwy 89, north of Truckee, CA. The snowmobile was sold a week ago, so I'm on my own power now. This would be my 3rd or 4th solo trip in sub-zero temps. Don't think that snowmobile at 35-50mph isn't cold!