The Xtherm, ahead of these entering the stores, I'm going to challenge the relative packed size compared to the Xlite.
I bought and used the Xtherm's predecessor the All Seasons. It certainly was warm, and I could tell the fabric underneath quite robust, and I am sold on the method used by Therm-a-rest of the reflective material, it does radiate heat back, feels warm to touch and makes more viable to not use a bag in warmer conditions.
I was not sold on the packed size. I found it huge, much larger than the Neoair than Therm-a-rest state on the product literature. So roll forward to the successors, the Xlite and Xtherm. You'd think Xtherm is only 430g/350g 23% heavier and 9"x4" / 9"x4" so the same packed size, the relative weights might be true but I'm not so sure about the relative size. The thicker base material and the extra reflective layers is only 80g on a regular? No thicker rolled size?
We'll see when it all hits the shops in more stock and for it to enter the field.
Ordered an X-lite small paid $103, with free returns in 60days. I'm going to try the tricks of others, place my backpack under my feet and I'm going to use a rollmat under the groundsheet of the tent to protect groundsheet and add about R=2 to Xlite's R=3.2 above to get roughly R=5.2
So from my ownership and use of the All Seasons, relative to the Prolite I used before, the thickness of the mat creates a problem which is any pillow you make FALLS OFF easily. The answer is EITHER to go up a size so the mat is right up to the edge of your tent so the pillow can't fall off, or do a little DIY glue on some velcro patches to hold a pillow in place, or (what I'm doing) is doing the opposite, going for a shorter pad and place pillow on the tent floor where it can't fall off. When I laid all that out (pillow from neck upwards, pack from end of pad downwards) it ends up my full body, and the small mat is 8oz/230g.
FYI I did see the 50% discount on the older Neoairs, but I decided worth paying $40 more for the Xlite because of slightly more insulation but also of an undocumented problem with the Neoair (and All seasons) which is the valve is digging into you, its facing upwards, the Xlite/Xtherm its pointing horizontal, if you imagine a short pad that valve is in your neck/shoulder.
I was looking around and I see Xtherms on backorder and due in the next few days. I'm interested in comparing lite-size (e.g. small and small) Xlite vs Xtherm and see if the weights and packed sizes stated are correct.