Does anyone use the Winter Mamba wide/long underquilt? And how does it compare or favor to the Jack's Old Rag Mountain? Both seem to be great top quilts. I like the fact that the Old Rag Mounatin can be used as both a top quilt and an underquilt. It seems to be versatile. The Winter Mamba seems to be more like a streamlined sleeping bag without zipppers.It seems to be more specialized. But it looks wider in the shoulders. So does anyone have any experience using this two different top quilts?