I have a RUSH 24 and a RUSH 12. I'm 5'8", and the GF is 5'3". She finds that the RUSH 12 is the perfect size for her and that the 24 is a bit large, but might be doable if she had to carry more stuff, so has tried on the RUSH 24 several times. (working in a store that sells them provides her ample opportunity to try them on) She finds though that after trying on the RUSH 24 several times now, that it is not comfortable for her and will stick with her RUSH 12 I find both fit me just fine and it depends on the amount of things I need to pack that will be the determining factor. That little bit of torso length makes a difference. The yoke straps for me were uncomfortable until I started carrying the bag slightly lower than my previous bags. Once I hit that sweet spot, the RUSH bags feel like they aren't even there when I wear them.