1 - Of the three LIS databases, LISA is the most focused on scholarly and technical literature, excluding news stories, book reviews, and the like.
2 - LISA has the best and most balanced international coverage. (But you might be disappointed by articles with translated titles that sound terrific, but which are only available in their original languages.)
3 - LISA provides a robust thesaurus
References: Thanks to the UIUC LIS Library LIS LibGuide