We used Chosen in an Australian news site which targeted South East Asia and Pacific island nations. 4 of the 11 language streams on the site relied on @font-face embedded fonts to provide support for displaying East Asian languages (Khmer, Burmese, etc).
Chosen helped us overcome a fairly major multi-browser issue where embedded fonts weren't being used inside <select> elements (oddly it seemed to work in IE6 but not IE7). Since Chosen transmutes the <option>s into style-able divs, this allowed us to use our @font-face fonts with very few issues. We ended up using it across the site for consistency (with a few exceptions) and all in all I think it provided a usability improvement for most of our users.
Chosen helped us overcome a fairly major multi-browser issue where embedded fonts weren't being used inside <select> elements (oddly it seemed to work in IE6 but not IE7). Since Chosen transmutes the <option>s into style-able divs, this allowed us to use our @font-face fonts with very few issues. We ended up using it across the site for consistency (with a few exceptions) and all in all I think it provided a usability improvement for most of our users.