You've been going back and forth on size for quite a while right?! I have 3 NF's MM, NF GM, Delightful MM and GM. I'm 5'6 and feel the NF GM is too big for everyday. I choose my Delightful GM for travel because it's so much more comfortable due to the strap. The NF GM is not comfortable when full. IMO the GM will be too big for you but that being said if you feel that you really need the space get it...you can always sell it if it doesn't work. I have only held onto mine because it's the old model and I paid so much less than what they cost now. I love the MM size...it's a great bag for everyday. Have you tried the GM on? Only you can decide what you want/need...trying on with your things inside is really the only way you will know for sure.