This issue has just been raised again:
What I plan to do is add a new tab to the WordPress (3.5) "Insert Media" popup dialog with all of the filtering options up see on the Media/Assistant screen (mime types, date ranges, categories/tags, enhanced search box, author). It's the right thing to do, but it's a significant piece of work that includes Javascript and Ajax elements. I hope to add it to version 1.2, two releases from now.
Thanks again for the suggestion and for using the plugin.