>a) proximity searches
>b) flexible weighting schemes
>c) ability to synchronize the text indexes via PL/SQL statement (instead of waiting for a schedule process to update the text indexes)
>d) native field type that references external files of numerous types (Word, etc), and allows their contents to be indexed as though part of the database

I believe that SQL Server's Full-Text Searching provides all of those features except (d).

-Mike