depends on your foot width I think. I have a medium to wide foot, so wearing the CB's is a bit tight so I went up half a size and its much better. but when i try on the vapors I have to stick with true to size. so.... i guess if u have narrow feet: cb's stick to size, vapors 1/2 smaller, wide feet: cb's up 1/2, vapors stick to size
not sure if that works for everyone tho =\