Yes, it's the Finder! You don't have to learn anything new
Apps like PathFinder, ForkLift or DiskOrder are nice, mature and have many great features. But you have to make a hard decision to switch and learn.
With TotalFinder you don't have to decide between the Finder and some replacement application. You get the Finder with all you already know plus some new handy features. You may selectively enable them as you progress with TotalFinder.
TotalFinder is not a replacement application, it is a plugin which improves the Finder's functionality. This offers better interoperability with other applications which usually expect the Finder to be your only file manager. We've all seen those menus with "Reveal in Finder" items, right?
The Finder is not going away any time soon and it has some very unique features, like Time Machine and Spotlight search. Every Mac has Finder installed. You are better to learn how to live with it than fight it. TotalFinder can help and make the Finder work better for you.