@Andy - The Vango Ultralight has an open cell foam lining which is "diamond cut" wgich I believe means it has holes cut in the foam to make it lighter. Vamgo do not give an R rating. TGO review indicates lack of trust for winter use. Personally I wouldn't use any pad which has gaps in the coverage for winter use. Personally, I wouldn't use a failure probable inflatable for critical use.If you are up a mountain, 10-15 miles from the trail head on a moonless night is a snow storm, you are not going anywhere and need to be very sure of your equipment. 2 12 mm CCF pads are a pain to pack, but weigh little (and cost little) and cannot fail(unless you let it blow away in the wind), If you're just a couple of miles from your car on fairly level ground, then all you risk is some discomfort while you hike out when it goes pear shaped. So failure prone equipment is not such a big risk. However, I would rather have one set of kit whcih suits the worst case and is no disadvantage in the milder situation.