I recently took my new Synmat UL 9 to Max Patch on the Appalachian Trail and it worked flawlessly. The temps at night ranged from about 20 to 25 but I didn't notice one bit. I am a restless sleeper but didn't bottom out once. This thing is amazing and I will give more reviews on it at www.letsgohikeit.com
This review was written in the old system and had content requirements that are different than reviews written today.