Exped Synmat UL 7

I have not yet used this enough to speak to it's long term durability, however, I am impressed with how comfortable this pad is. I have used a couple different kinds of Thermarests: the Prolite and an older basic model, along with the RidgeRest (sp?) foam pad, and was never so comfortable as I was the few nights that I spent on this pad in cold weather. The very first night I used it was unexpectedly cold because we planned poorly and didn't watch the weather. We had planned on 35 to 40 degree F temps but when we woke up our full Nalgene bottle was frozen solid and my in-pack Camelback was slushy. Later we learned the temps were about 22 deg F. I was in a sleeping bag which should have been only comfortable down to about 30 deg F based on previous usage, but was undoubtably helped by this pad to keep me comfortably warm to well below freezing. The following couple of nights it wasn't as cold, but still below freezing. Because it was the only piece of equipment that was different from previous trips I am sure that this pad helped my trip to be comfortable.
It takes up about as much room as a Nalgene bottle, weighs very little, comes with a nice repair kit in case of puncture, inflates quickly by blowing it up (MUCH faster than a so-called self-inflating Thermarest,) and appears to be much more durable than the NeoAir.
Not only that, but this is the first pad I have ever slept on where I have awoken with no tingling or soreness from lack of circulation. It was so comfortable to sleep on it that I actually overslept. I hope that this pad proves to be as durable as it appears and lasts forever. I really love it.
The only downsides I have identified are (1) the cost, and (2) the problem that some people have complained about where their sleeping bag slides around too easily on it. I haven't had the sliding issue, but then again I was on mostly level ground the nights I used it. There are a couple of loops on it where you can lash your bag to the top of it, but I didn't have to do that.
I have become a huge Exped fan. They really seem to produce top quality lightweight equipment. I also have their inflatable pillow and have nothing bad to say about it either.

This pad is among the best that I have used or tested. It's stated weight is spot on. It is warm to the stated temp. rating. I just got back from a 3 night/4 day trip in the Gila. The first morning was 22f (lots of humidity; ice all over the inside and heavy frost on the outside of the tent). I was using my Marmot Pinnacle 15 and wearing a complete base layer (with socks and beanie). I was just beginning to become cooler lying there talking myself out of the bag that morning. (I would definitely go back to my BA Insulated Air core if it were to be any colder.) I have owned the BA Insulated Air Core, the BA ClearView, the BA REI Sand Mountain Insulated Air Pad (same as the BA Insulated AC but with only 6 cambers instead of 7.) As far as sleeping comfort, I fine the SynMat UL7 at least as comfortable as the BA pads... possibly a litte more comfortable. The UL7 is just not as warm as the BA insulated Air cores. If it weren't for the ridiculous expense of this pad I would hands down say buy this one..... but this is crazzzyy (say it like Nacho Libre would) to ask this much. At this price EXped should include turn-down service! Oh, forgot to talk about durability: My dog is pretty hard on anything in the tent. This pad made it through three days of him clawing at it.
Update : During late summer of 2012 on the CDT (many nights on it by this point), I lost the check flap of the valve on the inflate side. Exped replaced this mat with a new one. Thanks Exped!

My wife complained after sleeping on my NeoAir pad one night, so for her birthday I ordered this pad and a NeoAir All Season pad for her to try as well. We both independently arrived at the conclusion that we like the Exped Synmat UL 7 the best of the pads - we both liked the baffles running lengthwise as well as the extra thickness (0.3") and the extra width (approx 1") when compaired to the NeoAir bags. Since we likely won't be sleeping below freezing anytime soon (young children with us), the R-value of the UL7 is more than sufficient for our needs. I like the flap valves that Exped uses on their bags, although I will definitely be investing in a shrink bag and shnozzle for inflating the pad in the future.
If you go on Exped's website, they explain that they use an actual synthetic insulator inside the pad (as opposed to the reflective barrier to capture radiant heat like the NeoAir bags), and Exped went the extra yard and laminates the insulation to both the top and the bottom of the bag so that it won't degrade over time from being compressed repeatedly. Whether this actually turns out to work is obviously yet to be seen, but as far as first impressions, the UL7 is a winner.
I've used this sleeping pad down to 35F paired with a Big Agnes Horse Thief bag, and the sleeping pad performed extremely well.

I have a Reg UL and a LW UL and I wouldn't go any where with out one. If I'm hiking or kayaking with my OR Advanced Bivy I use the regular size as it gives me a little more room, otherwise I use my LW for everything else. I like the extra comfit of the LW. I would highly recommend getting the schnozzle pump bag. I also have a Synmat7 Reg with the built in pump and using the pump bag I can fill the LW UL in a quater of the time it takes me to pump up the Synmat. You can also use the pumpbag as a dry bag to keep your mat in while hiking. I have had the reg UL for over a year and have used it in some pretty nasty places with just a tarp and no ground sheet (expecting to wake up on hard ground) but still no punctures. The material is a lot tougher than it looks. In summer I use a Therm-a-rest fitted sheet on my mats (a lot cheaper and easier to purchase than the Exped fitted sheets) as I don't like the mat material touching my skin, it can get a little clammy but the fitted sheet fixes that issue.
Great year round mat.