Bought these for my girlfriend, and was worried about reviews of them running small.  She wears an 8 1/2 and she says they fit perfect (after she got them on, which did require using the pull tabs).

After wearing them for awhile she commented that her feet were warm, but not sweaty.

Visually they're attractive, but they do LOOK like cushy socks.  Very tiny, compared to regular looking shoes.