Are they only of use to people who can sleep flat on their backs as if strapped to a gurney? I`ve spent many nights in rectangular bags and usually curl up on my side, just like I do in bed. I`ve always avoided mummy bags because they look cramped, but now I`m thinking I could probably still curl up just as long as I keep my legs together and curl the bag up with me. Is that true? I`m looking to replace my current summer bag with something more compact (lighter would be nice, but not the main idea). Besides the fact that mummy style shaves material, resulting in a lighter and smaller load, there seem to be a lot more options than for down rectangles. Better off with a blanket? Any related comments appreciaed- maybe there are optons I haven`t considered.