The holy grail of sleeping pads: NeoAir Xtherm or Exped Synmat UL?

The fabric on the Exped is actually significantly thinner (though, that still may not translate to serious durability issues). It is a 20D fabric, while the XTherm has 30D on the top and 70D on the bottom.

Both have a reputation for durability, but the 70D is definitely more bomber than any other lightweight mattress out there.

When you weigh the xlite, you are probably weighing some documentation and repair kit that is all rolled up inside it inside the stuffsak?.

My xlite weighs 12.6 oz without the stuffsak.

The xtherm is only a bit heavier, for the 70D bottom.

I carry a 2.5 oz 19×60" 1/8" CCF pad with my xlite to use under it to protect it.
During the day, I use the CCF as a sitpad
If I get a leak, I can double it over and have a 1/4" CCF torso pad

no complaints about the xlite

together, 15.1 oz and R of about 4, but more durable, and more versatile.

Unless camping on snow or such, dont need a 5.7 R value

After the initial problems with the Xlite, its been very reliable. Some have made whole thru hikes of PCT and AT with them without failure.

I used the xtherm all winter and it is super warm. If there's a better mat then it must rock you to sleep.

I weighed the Xlite without anything else, but there's a possibility that something was off, as I did this on the floor of REI. But is yours the regular or the small (or women's)?

But if you're right, then the Xtherm only weighs 2.7 oz more than the Xlite. Now I do agree with your recommendation of a 1/8" foam pad. I also use a Gossamer Gear thinlight which is 1/8" in thickness. I do this to prevent punctures but probably more so to help with slippage on the silnylon floor of my tent.

I guess I don't need a winter pad for the summer trips I do, but I will tell you that I'm always getting cold at night and this year I told myself I would do something to rectify the situation. I read somewhere online that conductive heat loss via the ground is more responsible for one getting cold than heat loss through one's sleeping bag. I think I believe this theory, as I'm always feeling cold through my Big Agnes Insulated Air Core pad.

You might take a look at "Lightweight Inflatable Sleeping Mats – State of the Market Report 2011" in the archives.

http://www.backpackinglight.com/cgi-bin/backpackinglight/airmat_sotmr_part1_2011.html#.UZqaDcpgs-U

I would pay particular attention to the section on compressed vs uncompressed R values — the Exped loses far less insulation when squashed than straightforward air-filled mats.