R-value new thermarest vs Down vs CCF

[Tordnado]

With the latest neo air Xtherm one get an R-value of 5,7 at 310 grams for the small size (upper body). How does that compare in terms of weight VS insulation with down underquilt. One would have to add an SPE to the thermarest so say 400 grams total.

Yes there are other factors than weight/insulation but thats not what I´m asking this time

[uncle_ray_ray]

With the latest neo air Xtherm one get an R-value of 5,7 at 310 grams for the small size (upper body). How does that compare in terms of weight VS insulation with down underquilt. One would have to add an SPE to the thermarest so say 400 grams total.

Yes there are other factors than weight/insulation but thats not what I´m asking this time

The large sized one is 1 lb. 6 oz. and costly..

[wisenber]

With the latest neo air Xtherm one get an R-value of 5,7 at 310 grams for the small size (upper body). How does that compare in terms of weight VS insulation with down underquilt. One would have to add an SPE to the thermarest so say 400 grams total.

Yes there are other factors than weight/insulation but thats not what I´m asking this time

The 310 grams would provide insulation for part of your upper body, but something would still be required for shoulders and feet. An SPE with no inserts might weigh 90 grams, but the wings to go in the SPE would probably be another 60-90 grams. That would be about 460-490 grams for upper body insulation down to about -10 C. Since a fractional UQ would also require something to insulate lower legs and feet, it is not necessary to include that added weight in the comparison.

Contrast the 460-490 grams of the Thermarest good to about - 10 C with a Leighlo 0 F UQ at 510 grams good to -17 C for an approximate comparison.
The Leighlo would cost about $40 more, but it would not require the SPE and wings. The Thermarest offers a ground option, but that also includes the risk of puncture or failure. The other difference would be that with the Thermarest, your body is on a pad, and with an underquilt your body is on the hammock fabric.

They'll both work, but I prefer the comfort and warmth of down to using a pad at temps that low.