at the moment I think the search filter is working really quickly, but AFAICT it takes into account only classes' (or properties or whatever list you're currently in) names. For someone looking for inspiration for how to model his or her own data, it would be great if the search also considered the scope notes and other documentary information.
It would indeed be a very good functionality. Unfortunately, at the moment, the search is limited to the information displayed in the list. But we retain this idea for a future advanced search possibility (issue #760).