Rating: 5 / 5
Recently purchased an Nunatak Arc Ghost and I love it. It has a one ounce overfill and third strap with a rating of +32 degrees. My previous down bag was a Mountain Hardwear Phantom +32. The Phantom has (according to manufacturer) 10 oz. of 800 down fill. That's 10 oz. to fill the top, bottom, foot box, hood, and draft tube. The Arc Ghost has 9 oz. of 800 down fill stock with an extra ounce in mine making it 10 oz. to fill the top, sides, and foot box. The same amount of fill and less space.
This is the first bag that is truly the rating it is stated to be. With the Phantom I always added 10 degrees to the comfort rating making it a +42 degree bag, but not with the Arc Ghost it really is a +32 degree bag. I don't miss the hood either with the Arc Ghost as I use a bivy sack and a beenie.
I almost deducted one point because the straps on the Arc Ghost are really long, but the fix was easy, just trim them, so no deduction needed. Also notable is the baffle height, 2 inches on the Arc Ghost and only 1 inch (maybe) on the Phantom. More loft, more down, more warmth.