This one will be short and sweet. I bought this pad(Therm-a-Rest Z-Lite Regular) to be a lighter weight alternative to my much heavier Therm-A-Rest Trail Long, and my Therm-A-Rest Ultralight. I purchased it in the "Limon" color. It is a closed cell foam pad with an egg crate design. Unlike most closed cell foam pads, this one folds up in an accordion style. It is 72 inches long and 20 inches wide. So a 6' tall hiker could stretch out on this one. The spec sheet at their website shows the weight at 14oz, but I weighed it out at 13.6 oz on my scale. While only 3/4" thick, the egg-crate design made it seem thicker to me. It has an R-value of 2.2, which is only slightly lower than that of the fabled "NeoAir" at 2.5.
The first night I slept on it was on the Ozark Highlands Trail, Hare Mtn.(section 3). The temperature dropped to about 45 degrees. I was in a Western Mountaineering Summerlite 32deg down bag. I was warm and toasty. I am a side sleeper, so I did notice that I was less comfortable than with either of my other pads. I purchased the "regular" size with the idea in mind that I could always cut away sections if I decided to go with a shorter length pad. With this pad, you could easily reduce the length in roughly 5" increments. Therm-a-Rest also sells it in a shorter verson which is a torso length pad at 51" and 10 oz. Also, they sell a 'Z seat", which is 13"x 16". The reason I bring this up is that I could cut away several sections, packing them as well, and have a good seat to set down on in wet conditions, then reuniting it with the rest of the pad for sleeping. I disliked that the pad folds up in a rather bulky fashion(20"x5"x5.5"), but I liked that I was able to attach it to the outside of my pack without worrying that I would damage it. This freed up a fair amount of room within my pack. For backpackers who want to use a smaller volume(and lighter) pack, this is an added bonus.
I only used it once, so I will no doubt revisit this review upon using it in different conditions. However, I already consider it a great value, at only around $40 at my local outdoor store. I will use this on all of my 3 season hikes for quite a while to come. The basic question is whether or not I would recommend this to my teenaged nephew for his Philmont hike this coming summer. The answer is a resounding YES!