Although the X Frame is impressively lightweight and compact, it has several drawbacks that restrict its use to a specific group of people. 1) The pad's air baffles are "body mapped" to fit someone about 5' 10" in height. Depending on how your body parts match up to it, the pad may not fit you. The pad is also the narrowest of the 20 we tested — it's 18" wide as opposed to the standard 20" width. Thus, wider people may not fit on it. 2) The pad is ideal for people who sleep on their backs and don't thrash about at night. You may not find the Inertia X Frame to be comfortable if you turn over frequently, sleep on your side, or curl excessively. 3) The pad's thin baffles and large open spaces do a poor job at insulating you from the ground below; the pad is best for summer use. In sum, the Inertia X Frame could be a good choice for summer backpacking if you're around 5' 10" and sleep on your back.
Our top rated ultralight pad is the Therm-a-Rest NeoAir XLite, which weighs 12 ounces in the 72" x 20" size. The NeoAir XLite is more comfortable, warmer, and more versatile than the Inertia X Frame. If you're counting ounces, we suggest the NeoAir XLite in size small (47" x 20"), which weighs only eight ounces (put your boots and backpack under your legs).