La Sportiva Skawma sizing

i'm looking to get a pair of skawmas but their size chart says a 42 is a woman's ten. I wear a size 11 street (43) but was planning on down sizing anyways, especially since la sportiva heels tend to be loose. Does anyone have these shoes and know how well they fit/ how accurate their size chart is? I have a big foot but fairly narrow so its hard sometimes to find well fitting shoes.