I don't like being constricted when I sleep, and this bag definitely gives me space to move around and breathe. I'm 5'3 and I have a size Regular (62" shoulder, 48" hip, 38" footbox). When you pack it ...
An upside of this thinking is that the footbox is roomy, allowing tired feet the chance to decompress in comfort - a pleasant change from some bags that take the ‘mummy’ cut to extremes.