2 things in particular : its case law database is richer than that of most of Doctrine's competitors ; and it (controversially enough) provides information on the activity of practitioners (such as their clients and cases). Review collected by and hosted on G2.com.
It does not cover well the legal field I specialize in - international arbitration - because its database contains judicial decisions only and no arbitral awards. Review collected by and hosted on G2.com.



