When it comes to warmth to weight ratio the sleeping bag is a better choice because you can seal yourself up in it, with no hassle, which retains your body heat. Your going to get more comfort out of a 20 d bag versus a 20 d quilt. And I'm referring to a single quilt, not the "whole quilt system" or extra clothes, beanie, and whatever else it takes to make it work, just the single piece of gear, one sleeping bag vs one quilt.
I would simply rather carry less gear. If I get cold with my bag I can put on my clothes, if I'm in a quilt and already wearing my clothes, then its going to be a long night. Trying to sleep while freezing your a$$ off is a one time lesson that I learned the hard way in the beginning. Yes this has made me gun shy, bias, and conservative, and a little close minded about the quilt systems. But I can say from first hand experience and time in the field that a 0 degree sleeping bag works during hunting season, and its as simple as blowing up the mattress and crawling in. If your new to backpack hunting, it will probably work for you too. Once you get time in the field you will find the threshold of both you and your gear. Then you can start experimenting with other options, but I warn you, if you constantly test the limits then you will reach them eventually and it sucks!
The temperature in the rocky mountains is really varied. It could be 30 d on a hillside, and a half mile lower in the bottom of the canyon it can be 20 d, there are tons of microclimates in the mountains, our weather stations and reports can't always keep up or be accurate. The animals know this and move accordingly, we don't usually have that knowledge til its too late so be prepared! The region your in also makes a difference, the Rockies are arid and cold, the Banana belt (WA, N Id) has milder temps and more rain. 30 degrees and above is forgiving, below 30 gets exponentially more critical.
I have seen youtube videos of Shug Emery sleeping in a quilt system in below 0 temps in a hammock, but this is only achieved with a whole quilt system. The system being a hammock, a quilt, an underquilt, and extra clothes. The underquilt is the key here, its uncompressed and offers a better warmth to weight ratio versus a sleeping pad, I think. But it takes 2 trees to hang a hammock and you can't run a stove
Rambler, I am interested in what your complete quilt sleep system consists of to get down to 0? How much does it weigh? I imagine a hammock and underquilt alone might be lighter than a sleeping pad.
Is the quilt ratings based on using it stand alone or with an underquilt?
Maybe the overall quilt system has a better warmth to weigh ratio than a bag and pad combo, I'm interested in hearing more about this system for cold weather hunts.
For you to successfully go down to 0 your probably using a hammock, underquilt, a quilt, and some extra clothes. Don't get me wrong this looks like a very comfortable and efficient system, but I think the problem arises when we try to combine the two systems in COLD weather. For instance like a quilt on top of a sleeping pad instead of on top of an underquilt in a hammock, or a sleeping pad on a hammock instead of an underquilt.