I find this bag very useful for temperatures from about 20 F to 45 F. I use it with different combinations of jackets, caps and hoods to match weather conditions. I am a side sleeper and have used an elephants foot for mountaineering for almost 50 years. I like having a jacket hood that you can breathe out of when on my side. It works great when there is limited space but this 17oz. is my normal go to bag. My old elephants foot weighed 28 oz.
I use a 12 oz. quilt for 45F to 60F and a sleeping bag liner for 60F to about 72F. Below 20F I use a traditional sleeping bag providing there will be a place to lie down flat. I have added down pants and my heaviest parka for a Bivy in the Hybrid bag below 20F but 10F is my cold limit for this guy. It helps me keep my weight below the other guys without giving up comfort.