I have found PF 4 to be very stable. It gives you a variety of ways to navigate file systems. The bookmarks bar is very useful--especially when combined with my Default Folder Favorites and Recent Folders. Tabs are a great thing in browsers and probably will be almost as useful for navigating files (PF needs a more complete open in tabs option. It is an excellent frnt end for Spotlight and its Preview capabilities are far superior to those of the Finder. It just makkes working with files a lot more efficient.