Therm-a-Rest - NeoAir XTherm (OG Version)

Great summary! FWIW my (particularly specific) alternate take on sizing is: having a Neoair Xtherm revolutionized my experience on the trail thanks to a proper nights sleep (including on snow) - HOWEVER my first one was standard width, and my brain never fully shook the underlaying feeling that I was about to roll off (obligate side sleeper, so always a degree of instability). I did use my pack to my back to help ease this, but very suboptimal, especially in a small or shared tent. Getting the wide version was the final peg in giving me a warm stress free sleep - the increased weight was negligible for me in this case. Of course everyone’s mileage will vary wildly, but sometimes it’s the myriad little things that make the difference - I always recommend trying to find a friend or rental you can try your top 2-3 options in the field before sinking the dough :)

It looks like you're responding to the convo above but the idea of using an inflatable for the torso with pack or equivalent on the legs/feet has many advantages. It's both lighter and has an inherent element of redundancy. If the inflatable fails beyond repair, there's still some kind of insulation for the torso. I just came back from a trip on which I used an old Xtherm torso pad with a GG folding pad that was part of my pack. The old Xtherm only weighs 269g and is much closer to the ground which puts less stress on the knees. The GG pad is 74g. The combo is significantly lighter than a regular Xlite *and* it has inherent redundancy. The Tensor Elite short isn't really a torso length. I'm 170cm and the Tensor Elite short is 160cm. It's too bad Nemo doesn't offer a genuinely torso length version.

I have previous generation NeoAir Xlite and XTherm pads (with the older valve that looks like a small black cylinder protruding from the pad. The XLite has a bit of that "potato chip bag" crinkle which I think has gotten better in the newer models. In terms of comfort, my Nemo Tensor is WAY more comfortable, but my first Nemo Tensor failed when it kept getting little holes where the dimples are located. The NeoAir XTherm is AWESOME for warmth. I took mine on my Mt Baker climbing/mountaineering class in mid July 2024 and it was great there, and I didn't seem to mind the comfort as much. Maybe I was just tired at the end of each day and didn't care! I have a Kilos AeroCloud Ultra on the way to try and compare, which will probably be my wife's pad when we go to Iceland this summer to hike the Laugavegeur. She has lower back issues and keeping her on a comfortable pad is very important. We're always trying to strike a balance between comfort and weight for her gear. I think the Rapide SL is another good pick. Hard to know which of all these options are the best.

For -5C and durability I would personally take the Thermarest X-Therm mummy. R7.3, 440gr (although mine weighs 460gr in reality), and a 70D material on the underside. Anecdotally, I can feel the cold seep through my Nemo Tensor Insulated (R4.2) from around freezing.

I kind of regret not buying a thermarest xtherm instead of the neoair I think. Fairly big R value difference: - neoair wide/regular mummy: R=4.5, 16oz - xtherm wide/regular mummy: R=7.3, 19oz 3oz (+19%) weight difference for 62% higher R value I backpack a decent amount in hot DC summer/falls though and felt the x-therm might just make me too hot.

I had both. Initially had Xtherm, sold it for Nemo and went to RW Xtherm. Xtherm is definitely warmer and more reliable - it has 70D bottom and there is something about the technology that just make it more warm pad than Nemo. Many people report that Nemo is sleeps colder than it should be and I am one of them. Jupiter Hikes states that the Mylar layers are sticking/freezing together in the Nemo pad so you need to pat it a little bit. I took my Nemo to -5 degrees which is something it should handle pretty well but I was cold and I am a cold sleeper like you.  Comfort - do you prefer hard bed or you sleep well in extra soft hotel mattresses? I prefer hard bed so Xtherm is more comfortable for me, but more people prefer Nemo. To me it felt like I was sinking into the mattress and I am not a heavy person (65kg for reference).  If you are a side sleeper, consider switching to regular wide version as it has extra space for your knees. It weights more but hey, if you can get a better rest, you can walk more milage easily so it’s worth for me

Xlite has only 30D bottom so it’s less durable. How much of an actual difference there is between 30D and 70D fabric is beyond my knowledge but the more durable the better I guess.  Nemo is less noisy but I wound not call my Xtherm a noisy pad. These winter pads that use some kind of Mylar or reflective films will always be noisy to some degree but I find it okay 

I had both. Initially had Xtherm, sold it for Nemo and went to RW Xtherm. Xtherm is definitely warmer and more reliable - it has 70D bottom and there is something about the technology that just make it more warm pad than Nemo. Many people report that Nemo is sleeps colder than it should be and I am one of them. Jupiter Hikes states that the Mylar layers are sticking/freezing together in the Nemo pad so you need to pat it a little bit. I took my Nemo to -5 degrees which is something it should handle pretty well but I was cold and I am a cold sleeper like you.  Comfort - do you prefer hard bed or you sleep well in extra soft hotel mattresses? I prefer hard bed so Xtherm is more comfortable for me, but more people prefer Nemo. To me it felt like I was sinking into the mattress and I am not a heavy person (65kg for reference).  If you are a side sleeper, consider switching to regular wide version as it has extra space for your knees. It weights more but hey, if you can get a better rest, you can walk more milage easily so it’s worth for me

Ha, same. Started with the 'ol cheapo Klymit Static V, moved to the small mummy Therm-a-Rest XLite NeoAir for a couple years, then figured I'd get a wide to see if that helped with side sleep comfort so my butt and knees weren't off the edges (& went extra warm because may as well eliminate redundancies) with the Therm-a-Rest XTherm in reg wide. No dice. Tried a friend's Nemo Tensor, and wasn't for me. Tried the large women's Sea to Summit Comfort Light Insulated air - dimples felt odd and was too thin; no better than my old mummy xlite for overall comfort even with the wider shape. Running out of budget to throw in for the S2S Ether Light XT test and given my experience with the Comfort Light, wasn't convinced it was the move. Still haven't tried vertical baffles like the Expeds, and maybe that'd do fine, but instead just went all in on the reg wide chonky Neoloft... and good god. With that soft knit stretch top, slept a like the coziest dreamy log for 8.5 hours first time I took it out (and then 6 the next, but only thanks to a disruptive woodpecker. Nature!) I hesitate to mention/recommend it here as it kinda undermines the whole forum topic (ultralight) with its extremely-not-ultralight weight. But packs just as small as my reg-wide XTherm and as a bike camper, pack size matters more than strictly weight so I'm sticking with it.

Personally (I’m in my 40s and a side sleeper) an Xtherm or Xlite is one of my favorite purchases. But everyone has different needs. I’m a fan of not buying new things until you actually need them. Or you are sure that your goals will outgrow your gear. A cheap inflatable is definitely not worth it.

If you have something you’re happy with, decline to participate in outdoor culture’s fascination with over consumption. That said, getting an expensive XTherm pad completely changed the range of temps I’m stoked to be out in.

It depends on your conditions. I have a full length Xtherm for 40f nights but the half sized Xlite (now discontinued?) for 60f nights. It’s great, good weight savings. Sometimes put my backpack under my feet, but generally I’m not that fussy.

The Xtherm was a total game changer for me. The warmth from the reflective technology makes a huuuge difference

Thermarest Xtherm for me.

15F frequently or “just in case”? This is my set up: Xtherm Thermarest, 0F Enlightened Equipment Enigma (bought in 2021, I’ve heard their quality is decreasing), 90gsm alpha fleece sleeping layer. SMD’s Gatewood Cape , which offers minimal heat trapping. I feel good to 20F. I’d be uncomfortable but ok at 15F. If my tarp isn’t cutting the wind well enough, I’ll also sleep in my rain layers. There’s no one “true”/“best” way. It’s going to depend on your body, your baselayers and how much comfort you want. Alpha fleece is incredible, but only if you take care of it and have a wind layer. 850 or better down is going to be a good thing to look at. Lighter materials need more care/are more fragile. Thicker material on a sleeping bag will also cut wind better, but be heavier. Managing sweat and condensation is also going to be a big part of being warm. https://preview.redd.it/ql5u7bcm7b6f1.jpeg?width=1179&format=pjpg&auto=webp&s=3447a515da55f7c7c722dd870512568afebd5473

The best warmth to weight ratio pad on the market is the Therm-A-Rest XTherm. Great pad, really fucking warm though so only get it if you sleep cold. It’s pricy but if you buy it at REI it’s got a year of warranty, which you might really need, especially in the desert or even just if it gets all nasty from being wet later on. It’s a steal imo.

XTherm seems to be the gold standard currently and is what I have. I have nothing but good things to say about it - super warm, super light, decently comfortable, and (from my experience) durable