I’ve used the Thermarest NeoAir XTherm for a number of years and it’s become my all-year-round sleeping mat. It is light enough and packs down small enough to work for summer and three season use compared to other mats I would have considered while providing more than enough insulation for any winter trips I go on. This is a review of my past experiences of the XTherm combined with new opinions after using the new 2020 model with the Winglock Valve.

The mat itself it absolutely brilliant. I have tested it on a wide range of trips across the years from summer bivy bag trips to winter bothy trips. I’ve used it in tents down to -15 degrees in the winter and never felt any discomfort. It’s arguably the only piece of kit I pull out of the cupboard for every overnight trip, no matter what. I know that some summer mats are lighter in weight and have slightly smaller pack sizes but they also have lower r-values and therefore higher temperatures limits meaning their use is limited to the conditions. The XTherm does not have this problem in the sense that it can only be used in winter conditions, it works just as well, and is still just as comfortable in summer.

The feel of the mat and the materials used are great. There is always going to be a shiny feel and a bit of a slippery effect on a tent floor but the XTherm is much better than many other mats I’ve used in regards to this. I have slipped down the tent a few times when I’ve had to pitch on uneven ground but I can never tell whether it’s my sleeping bag or the mat on the tent floor that’s caused this anyway. Generally speaking, this is a rare event and on flat surfaces I don’t find myself slipping off the mat much and I know that I do move around a lot. Despite the use of the insulation and the 30D fabric on the upper I’ve not had the ‘crisp packet effect’ where the mat makes excessive crinkling noises, unlike some of the lightest mats out there. The insulation seems amazingly thin and is hardly noticeable, even when the mat is deflated but it does an exceptional job of keeping out the cold. From cold stone surfaces to tent pitches on snow in sub-zero conditions this mat has never felt anything less than comfortable which is a massive advantage of this mat. The durability of the mat is exceptional. I’m not particularly careful with kit and since I’ve used this on wooden sleeping platforms, in bivy bags and on the floor under tarps it’s impressive that it doesn’t show many signs of wear and I can happily say I’ve never had a puncture either. The combination of 30D and 70D fabrics allow durability and lightweight to be pretty well balanced here.

The Winglock Valve is the new feature on this XTherm, along with the rest of the new Thermarest range. The head of the valve is a little larger but it still just twists open and you can attach the pump sack provided to inflate, or if you’re leaving that behind you can start blowing. The improvement in my eyes is that it’s now a one-way valve so you can put air in without it escaping, making life much easier when you’re tired or cold and not at your best when setting up camp. You don’t actually do anything with the Winglock until you come to empty the air out of the sleeping mat after use. To release the air you twist the ‘wings’ then open the valve to dump the air out. Having to do two things in order to release the air takes next to no time but doesn’t really serve much of a purpose in my mind either. Unless you need the added security of knowing air won't start leaking if you knock the valve, which I’ve never had happen in hundreds of nights on other reliable Thermarest mats, it just adds another step in for users.

I had read a few reviews online before using the new valve and understand why people are saying the valve is over-engineered. However, I don’t mind the new Winglock. As with any new valve on a mat, even between different brands, it takes a bit of getting used to but it’s not a hindrance in any way. When time is crucial when you’re tired at the end of a day there is no difference to the old valves in using the new Winglock system. When expelling the air from the mat the morning after it simply takes an extra twist and you’re back to normal anyway. In summary, it may be over-engineered but in practical terms it makes very little difference to the user and the one way vale for inflating is an obvious improvement.

This links in to the new Pump Sack Thermarest have provided with the mat. It has a greater capacity than the older version and clips onto the Winglock valve. However, I found that I had to be careful so the sack didn’t pop off the valve when rolling it up to inflate. Due to the one-way valve it doesn’t allow any air to escape but can be a little annoying at times. I know a few people complained about the old pump sack not staying on the old vale but I never had any trouble with this so this new version may improve for me when it’s had more use. I generally found that it took between 7-9 goes with the pump sack to fully inflate the mat.

All Thermarest mats have now been tested to the new ASTM F3340-18 standard which is a new internationally recognised test for working out the r-value, or level of insulation for sleeping mats. In simple, practical terms the new Xtherm has not changed. However, since all mats are now tested in the same way many of the r-values have changed. In Thermarest’s case many have increased on their original tests but in reality, the mats will still be the same as the older versions in terms of the amount of insulation you get and the warmth you feel.