For winter it looks like the REI FLASH All Season insulated mattress at 1 lb. 3.4 oz. is a very good deal.
It has an R 5.2 insulating value and at the weight it likely is only beat by the Thermarest Neo-Air X-Therm for warmth-to-weight. but All Season FLASH price is considerably less.
An REI customer service rep told me REI will always stand behind any mattress that has a leak at the welds. (emphasis mine)
I may get one but for sure I am getting the 3 season Insulated FLASH air mattress this summer on the next 20% sale.

