Okay, my buying gears have begun whirring and I need some advice. The goal: a lovely 20 degree F rated quilt or bag. Money is not an issue. Weight, of course, is paramount. I'm somewhat of a cold sleeper, so I don't want to push the actual comfort boundary. In general, I am a happy quilt user. I use the Nunatak Arc Edge for warmer weather and the JRB High Sierra Sniveller for colder weather (though I wish I had purchased a Nunatak Arc Expedition instead). I expect to layer with a parka or hat, as well as pair with an appropriate pad, so quilts in colder weather are fine with me.
I'm trying to choose between the wonderful 0.8 Quantum Arc Alpinist 5'10" quilt, and a standard bag like the WM Ulralite. It looks like a fairly significant fill weight and overall weight difference, 11 oz. vs. 16 oz. of fill, and 21 oz. vs. 29 oz. respectively. Have folks found the Arc Alpinist to be a truly comfortable 20 degree quilt in comparison with a similar bag?
Thoughts/experience, most welcome.