I'm a power user, and strigi for me ends up with WAY WAY too much data.
In some folders (desktop for example) it's practical for me to index files.
In other folders (project folders, massive directories with tons of svn repo's/full svn checkouts of other projects etc) it'd be very nice to index only the directories. For me to be able to pull up a directory quickly is extremely practical, but the index overload of indexing every file in those directories is just way too much. Maybe even an option to change depth to scan in those directories.
Right now strigi is scanning the entire source repository for qtCreator, because that directory is in my projects. qtCreator also links in tons of Qt headers, and I have the Qt development version there too, that directory is 4gb in size. I could block scanning that directory altogether, but it'd be nice to pull up krunner, write qtcreator, and be given the option to open the directory.
I could go through and disable subdirectory scanning for all my projects (manually clicking off all subdirectories), which would help quite a lot I imagine, but I have tons of projects set up this way. And in general I know where the content I'm looking for is, I just need a quick way of getting there, rather than browsing through folders.