The NeoAir XLite is exactly that---LIGHT!!! That coupled with the fact that it packs down to about the size of a Nalgene and has a pretty decent R-factor makes this pad my definite go-to for 3 season camping. I tend to sleep cold and was surprised how warm I slept on a 30 degree night in my 40 degree sleeping bag. If you're looking for a sleeping pad that weighs less than a pound, doesn't take up too much room in your pack, and has a pretty darn good R-factor, this is the one for you.
"They should just call this the "MEDIUM" Neo Air Xlite. Identical except for length."
OK guys, this is the same as the Neo Air Xlite, except it's 66", which falls between the "short" (47") and "long" (72") on the regular Neo Air Xlite.66" is 5 foot 6, for those of you who are slow at math. The weight is listed at 12 ounces but it should be about .3 ounces lighter. NOTE: Since the edges of these inflatables compress a bit, you should be 5' 2" or less if you're expecting head-to-toe comfort from this length.