Therm-a-Rest NeoAir XLite NXT vs Sea to Summit Women's Ether Light XT Insulated (2026)
NeoAir XLite NXT vs Women's Ether Light XT Insulated on the makers’ published figures: R 4.5 and 370 g against R 3.5 and 495 g, 3 in against 4 in thick, 72 in against 66 in long.
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Two air pads, two different trade-offs#
The Therm-a-Rest NeoAir XLite NXT (370 g, 13.1 oz, Regular) and the Sea to Summit Women's Ether Light XT Insulated (495 g, 17.5 oz) differ on paper in warmth, weight, thickness and size. The NeoAir is warmer and lighter: R 4.5 against R 3.5, and 125 g less. The Ether Light is thicker: 4 in (about 10 cm) against 3 in (about 7.6 cm).
The Ether Light here is Sea to Summit's women's cut; the NeoAir XLite NXT Regular is sold as one unisex pad. R-values and weights below are the makers' published figures; the Ether Light's size is from its retailer listing, because Sea to Summit's page gives none. Sea to Summit now sells the Ether Light XR Insulated in its place. RidgeNote has not used or tested either pad. Therm-a-Rest lists the NeoAir XLite NXT at $209.95; no list price for the Women's Ether Light XT Insulated is on record, so this page does not compare prices.
The short version#
Choose the NeoAir XLite NXT if warmth for the weight matters most, if you camp into the shoulder seasons, or if you need a pad longer than 66 in. On the published figures it is both warmer and lighter.
Choose the Women's Ether Light XT Insulated if you sleep on your side and want more thickness under your hip and shoulder, 66 in is long enough for you, and R 3.5 covers the nights you camp.
The specs, side by side#
Weight: NeoAir XLite NXT Regular 370 g (13.1 oz); Women's Ether Light XT Insulated 495 g (17.5 oz). The NeoAir is 125 g (about 4.4 oz) lighter.
R-value: NeoAir 4.5 (ASTM F3340); Women's Ether Light XT Insulated 3.5.
Thickness: NeoAir 3 in; Women's Ether Light XT Insulated 4 in.
Size: NeoAir XLite NXT Regular 72 x 20 in (Therm-a-Rest); Women's Ether Light XT Insulated 66 x 21.5 in (retailer listing).
R-value: what the 1-point gap means#
R-value measures resistance to heat flow into the ground. ASTM F3340, published in 2018, gave pad makers one test method. Therm-a-Rest names it for the NeoAir's figure; no standard is given here for the Women's Ether Light XT Insulated, so treat the comparison as close rather than exact.
R-value is not a temperature rating. As a rough guide for a whole sleep system, R 2 to 3.9 covers three-season trips down to around freezing, and R 4 to 5.4 suits shoulder-season nights down to around 20°F. That puts the Ether Light in the three-season band and the NeoAir in the shoulder-season band. You can close the gap on a cold trip by laying a foam pad under either one; R-values add. A Therm-a-Rest Z Lite Sol (R 2.0) under the Ether Light gives about R 5.5, and RidgeNote's R-value chart lists the other pads in the catalogue by band.
Both makers sell warmer pads. Therm-a-Rest's NeoAir XTherm NXT is published at R 7.3, and Sea to Summit's Ether Light XR Insulated at R 4.1.
Thickness, length and side sleeping#
Side sleepers put most of their weight on a small area at the hip and shoulder. A thicker pad gives more room before those points press through to the ground. At 4 in against 3 in, the Ether Light has an extra inch.
The Ether Light is also 6 in shorter and 1.5 in wider than the NeoAir. For back sleepers, weight spreads over a wider area, and either thickness is usually enough. How a pad feels is personal, and neither maker publishes a measure of it.
Noise#
Some insulated air pads crinkle when you move. No standard measures pad noise and neither maker publishes a figure, so RidgeNote does not rank these two on it.
Who should skip which#
Skip the Women's Ether Light XT Insulated if you camp on frozen ground, sleep cold, or are taller than its 66 in: R 3.5 is in the three-season band.
Skip the NeoAir XLite NXT if you sleep on your side and have had hip or shoulder pressure on 3 in pads; the Ether Light's extra inch is the reason to choose it.
A third option for side sleepers who also want warmth: the NEMO Tensor All-Season (522 g packed, 440 g for the pad alone, R 5.4, 3.5 in, MSRP $219.95). On the published figures it is warmer than both and, pad for pad, 70 g heavier than the NeoAir, 55 g lighter than the Ether Light, and half an inch thicker than the NeoAir.
FAQ#
Which pad is warmer? The NeoAir XLite NXT, on the published figures: R 4.5 against R 3.5.
Which is lighter? The NeoAir XLite NXT: 370 g against 495 g, a 125 g difference.
Which is better for side sleepers? On thickness, the Women's Ether Light XT Insulated: 4 in against 3 in.
Which is quieter? Neither maker publishes a noise figure, and no standard measures it.