Since I've never seen any user feedback about these mats here (or anywhere else for that matter), I thought I'd share my tuppence worth on these inflatable mats as they have now seen a fair bit of use (I shall spare you my usual taunting about the local weather ). A bit of context first: I am currently living in a country where Therm-a-Rest or Exped inflatables are simply unknown. Mail order is an option but big ticket items get you whacked with custom fees and massive shipping costs which does skew the comparison with anything bought on Aliexpress. So, I've got three JR Gear mats (yes, yes, I know... but my definition of a dual use item is that I get to use something along with the rest of the family and my excuse is that some very tired and bulky self-inflatables needed replacing): a mummy R 5.0 Insulated Traverse Core (got to love these names!), an uninsulated R 3.0 Traverse Core rectangular one and a 122cm R 3.0 short mummy. Long story short, I was after a R 3.0 short mummy but the thing was nowhere to be found on Aliexpress so I got an R 5.0 long mummy instead, then resigned myself to buying a regular R 3.0 in the not-quite-fulfilled hope of cutting down on weight and bulk before finally finding the short R3.0 mummy on clearance on a Japanese site... Left to right: 1.5l bottle, insulated mummy, non-insulated rectangular, non-insulated short mummy The mats all use the same 75D nylon fabric throughout and are roughly equivalent to a Therm-a-Rest Trekker or a Multimat Adventure. Top fabric has a PU coating while the bottom one has a TPU membrane making it quite sturdy. These are not your space age ultralight mat that need babysitting. Indeed, they have repeatedly survived close contact with a lively three-year old who treats anything inflatable as a bouncy toy or a trampoline! The main difference between the two versions is that the R3.0 only uses an "IR reflective" coating on the inside bottom while the R5.0 adds Primaloft with slightly heavier filling in the torso area according to the brochure. A little warning about advertised weights: these are rather optimistic and all my mats are over the official values. R5.0 mummy weights in at 593g (instead of 570g), the R3.0 rectangular at 534g (instead of 525g) and the R3.0 short mummy at 340g (instead of 315g). For what it's worth, the stuff sacks are cut from the same fabric as the mats and are around 15g. They are pretty thick (9cm) and I find all three comfortable if a tad slippery at times but I guess that depends as much on the sleeping bag as on the mat itself. Some people dislike the drop below the knee with short and thick mats but I've not found this to be a problem in my case. They may be a little narrow if you tend to move around in your sleep but 51cm is a pretty standard width and they have a wider XL rectangular R3.0 version. Like all inflatables, the ideal amount of air will vary from user to user, I tend to inflate fully and then deflate when I'm lying on top to find my sweet spot. Given the volume, these can take a while to inflate, especially if you are tasked with inflating all three after pitching the tent. This, along with the low bulk and weight, is probably a factor in making the short mummy my favourite of the three although the last time I used it I did notice (for the first time) a slight but rather nasty taste of chemicals which was not the case with the others (possibly the reason it was discontinued and on clearance!). The valves use by JR Gear are just a little wider than the Therm-a-Rest ones so the DIY inflator doodah made from a bottle cap and a rubber gasket needs a slighter wider 22mm hole to give the rubber some room to expand. Are they really R 5.0 and R 3.0 as advertised? I can't really say and local temperatures don't really put them to the test. The lowest temp I've taken one of them (the R 5. 0 which was the only one I had at the time) is 4-5 degrees and the insulation was more than adequate (as it should be!). It'd take these values with a grain of salt just like any manufacturer's self-proclaimed R values. Overall, I like both mummies. The full-length R 5.0 is at the upper end of reasonable weight and rather bulky but nothing outrageous for a winter mat (provided it works as advertised,). As for the short R 3.0, it packs nice and small and the weight is pretty good. The rectangular R 3.0, on the other hand, is something of a disappointment. While it is a lot less bulky than the insulated mummy, it's not a lot lighter and no more comfortable. It takes forever to inflate and just doesn't seem to have any real advantage over the other two mats. As a result, I'll probably shorten it to something around 150-160cm in order to cut down weight and bulk while still offering more acreage than the short mummy.