Different philosophy (linguistic approach), different layers of grammar tagged (mine is only syntax, theirs has more). There will be a long multi-authored article comparing the databases that will come out next late spring/summer in the Journal of Semitics (South Africa). It is based in the presentations about the three syntax databases (ours, ETCBC, and Andersen-Forbes) given at the IOSOT conference in S.A. last September.
With apologies, more than this would take too much space for the forum.
Professor, Hebrew and Northwest Semitic Languages
Dept. of Near and Middle Eastern Civilizations
The University of Toronto