My torso length is right on the borderline, and there's no overlap shown between the sizes. FWIW, a medium fits me in a larger Osprey pack, or an M/L in an Osprey daypack; S/M is too short, as are most non-Osprey daypacks. (Size 3 in Macpac fits too, as does the larger Dan Durston pack.) I'm ~5'11" tall and often find hipbelts verging on too large, and shoulder straps too far apart. GG is unknown here in Oz, so I cannot look at anything. Which size is more likely to fit?