"Strapped to the outside of your pack, you'll never notice the miniscule weight of this pad. You will notice, however, the difference when you're sleeping. It does a wonderful job keeping you warm even on the coldest ground, and it provides great padding for it's weight and bulk because of its egg-crate design. If you are one whose feet get cold, you may want to opt for the slight extra weight of the R-size Z-Lite, but for me, the S-size and a Thermarest Lite-Seat for a pillow (an extra 3 ounces) does the trick in any weather and on any terrain.
Total weight (Z-Lite S + Lite-Seat): 14.5oz
MSRP (Z-Lite S + Lite-Seat): $54.90"