Path Finder Per-Folder View Settings
The implementation of per folder settings took over two months of work. To accomplish this we used a Cocoa technology introduced in Tiger called Core Data. Unlike the Finder (with its notorious .DS_Store files) we use no hidden files, we do not require files scattered around in every directory, and no helper files will ever silently appear on your network shares or external hard drives.
Path Finder 4.8 will store its visual per-folder settings in a centralized SQLite database located in ~/Library/Application Support/Path Finder/CoreData.
It looks like the settings are keyed by directory ID and volume ID.