Scott Springer wrote a review of Exped SynMat UL on July 21, 2014
Familiarity: I've put it through the wringer
This was a welcome upgrade from my 1.5" self-inflating Thermarest. The packability of the Synmat UL is virtually unrivaled and was the primary reason for purchasing. It is pretty light (without being crinkly and plasticky like the Thermarest options). Packs down to something about the size of a 1-liter bottle, and still has enough insulation to keep me warm well into the extreme ends of the three seasons.
After several seasons of use, I'm pleased to also report that it allows me to get some of the best on-trail sleep I've ever had. By carefully adjusting the amount of inflation, I'm able to get the mat squishy enough to where my butt almost touches the ground, allowing my spine to assume a more natural position while I sleep. I've used it mostly in 3-season weather down to 25 degrees without any discomfort temperature-wise. The 2.8 inches of cushion feels downright luxurious.
At first I was super careful with this, but have become increasingly more confident in it's ability to withstand abrasion and puncture. I've not had a problem yet. Mostly it is in a foot-printed tent, but it has also endured the bare wood of some Adirondack shelters without problem.
The last trip was a measly car camping trip, and I was racing a fellow camper to inflate our pads. I over inflated mine and the adhesive holding the baffles together failed, resulting in a giant tube running half-way up the center of the pad. Super uncomfortable. Fortunately I was able to spin the pad 180 degrees and sleep with the big bubble between my legs, but the pad is definitely ready to be replaced. I will probably stick with this model.