I used a NeoAir this year (not Xtherm). As far as comfort, no problems. Seemed to insulate reasonably well. It does pack small and light. On the bad side, it's noisy and was very slippery with my sleeping bag. I had my tent on a light slope one night and was constantly sliding off. Maybe place a light foam pad on top? The width, well I wouldn't say it's a problem, but you'll be constantly reminded you chose the minimalist route. I may just use it again next year, but I'll probably at least see what else is out there.
