NEMO Tensor All-Season vs Therm-a-Rest NeoAir XTherm NXT

This is an unusually clean comparison, because the usual trade-off has been removed. Both pads are 72 x 20 in regulars, both weigh 440 g by their makers' own minimum-weight figures, both come with a pump sack, and both are backed by lifetime-class warranties. The entire decision is one published number and the price attached to it.

Side by side

Identical weight, different warmth

NEMO lists the Tensor All-Season Regular at 440 g minimum weight (522 g packed with its sacks). Therm-a-Rest lists the NeoAir XTherm NXT Regular at 440 g. Those are not approximately equal; they are the same figure, from two makers using the same 72 x 20 in footprint.

So the grams argument that normally decides a pad comparison does not exist here. What you are choosing between is R 5.4 for less money and R 7.3 for more, at no weight cost either way. Against our reference pad, the Tensor All-Season saves 240 g (8.5 oz) vs the Therm-a-Rest Trail Scout (Regular) at Value 1.8/10, and the XTherm saves 240 g (8.5 oz) vs the Therm-a-Rest Trail Scout (Regular) at Value 1.7/10 — identical grams saved, different value figures, because the list prices differ.

What R 5.4 and R 7.3 actually cover

R-value measures resistance to heat flowing out of you into the ground, and the ground pulls heat roughly twenty times faster than still air does. More R is always better; the question is where the extra stops being useful.

The honest reading: R 5.4 covers every night most backpackers will ever have. R 7.3 is for people whose pad is lying on snow. If you are not sure which of those you are, you are the first one. Our R-value guide sets out the bands in full.

Who tested the R-value, and how we know

Thickness, shape and noise

Thickness. NEMO lists 3.5 in on the Tensor All-Season; Therm-a-Rest lists 3 in (7.6 cm) on the XTherm NXT. Half an inch sounds trivial and is not, if you sleep on your side: it is the margin between a hip that bottoms out on a compressed pad and one that does not.

Shape. Both are rectangular in the Regular. NEMO also lists a Regular Mummy at 400 g for the All-Season, which is 40 g lighter at a lower list price — worth knowing if you want the taper and do not sprawl.

Noise. Neither maker publishes a figure, so we will not pretend to one. What both publish is construction: the Tensor uses NEMO's spaceframe baffles in 20D recycled nylon, and the XTherm uses Therm-a-Rest's triangular core matrix in 30D ripstop. Whether one is quieter than the other in your tent is not a spec-sheet question.

Fabrics and warranties

The XTherm has the tougher underside: 30D ripstop HT nylon on top and 70D nylon on the bottom, which matters because a winter pad spends its nights on frozen grit, ice crust and the occasional buried stick. The Tensor All-Season is 20D recycled nylon on top and 40D on the bottom.

On warranty, both are strong. Therm-a-Rest lists a Limited Lifetime Warranty. NEMO's Adventure Forever Guarantee is a lifetime warranty against defects. Both include a pump sack, which matters more than it sounds: inflating a high-R pad by mouth puts a litre of your breath inside the insulation every night.

Grams per dollar, and the third option

The Tensor All-Season is the better value of the two on this site's rubric, because it delivers the same grams saved for less money — the same MSRP band separates them at list.

There is a third answer, though, if the real constraint is money rather than season: the Big Agnes Rapide SL Insulated publishes R 4.8 with 4.25 in of loft in its spec table, at 510 g (1 lb 2.0 oz) and the lowest list price of the three. It is 70 g heavier and a touch cooler, and it is thicker than both. For three-season use with occasional frost, it does the job for less. It leads our budget pad ranking on exactly that argument.

And if winter is genuinely once or twice a year, stacking a closed-cell foam pad under a three-season air pad adds R for very little money — the arithmetic is on best winter sleeping pads.

Who should buy which

If you are choosing between the XTherm and its three-season sibling rather than against NEMO, that comparison is on NeoAir XLite vs XTherm.

What we cannot tell you

Neither maker publishes a puncture rate, a baffle-failure rate or a decibel figure, and those are the three things owners argue about. We rank on published, sourced specifications, so we can tell you the XTherm has a 70D bottom and the Tensor a 40D one — and we cannot tell you which one survives three seasons of your particular campsites. Nothing on a spec sheet answers that.