I have the Kaiju's in 10.5. I wear all my Nike's at 10.5 except for my soccer cleats. I wear them small. When I tried them on at first they were a bit uncomfortable, bordering painful. I wore them and walked around in the store for about 15 min. Then took them off, let my feet breathe a bit and tried them back on. From that point on they feel great. So if the 6.5 doesn't feel better after walking around in them for awhile, then I suggest the 7s.