Montane Black Ice Jacket

Anyone with winter experience using the jacket in a winter setup with a half bag? Seems a little light on loft for this use, but the quality of down may compensate--

  

The loft doesn't look like much, you have to look at how much down is in the jacket. I personally own this and have used it in -20 F belay situations and have been incredibly warm. I would compare it to the Mammut Ambler for warmth.