I have the Lost Ranger and the insulated air core pad.

1.) The comfort of this system is amazing. I am a side sleeper who tosses around a fair bit, and I love waking up still on the pad. Also, amazingly well rested.

2.) The Lost Ranger is in no way a 15 degree bag. On Big Agnes's own website they say it has something like 14oz of 650 fill down. They sell a much more expensive bag which has the same size cut as the lost ranger, but is filled with 15 oz of 800 fill down. Temperature rating? 15 degrees. Go figure. At any rate, I've been cold in my Lost Ranger at 32 degrees. The silver lining is that with 70" of girth, there is ample room for layers and liners.