My experience with the partial UQ (a Yeti in my Blackbird) is that it's worth the weight, money, and space savings. I always carry 1/2 a z-rest (6-8 sections) anyhow, so I have leg & foot insulation if needed. The combination of 20 degree TQ, 20 degree partial UQ, and the z-rest under my legs & feet has been nice & toasty into the high teens (as low as I've tried it)
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