You only really benefit when you use it a while and know all the key bindings by heart. Most of these seem pretty minor but when you get used to them you totally miss them when you don't have Total Commander available. And it's hard to explain to people, similar to explaining why one uses Dvorak layout or a Tiling WM to someone who has never thought about using those. Some examples:

- selecting files to work with. add, remove to your selection by pattern or manually (e.g. all *.jpg files except the two largest) and work on those

- move files to subdirectories without first creating a subdirectory (it creates it on-the-fly)

- multi-rename tool. select some files, rename them (with auto-incrementing counters, regex, taking substrings of the original name, etc). This is the killer feature for me (e.g. rename files with timestamps like dd-mm-yy-something.jpg to yyyy-mm-dd (SOMETHING).jpg or things like that. Oh and you can use fields from metadata too (id3, exif, ...)

- very fast integrated text/hex viewer with selectable codepages, ansi/ascii switch, and support for images and other multimedia files

- incremental search in file lists

- directory sync. compare and sync different directories by copying files one way or both ways

- everything done via keyboard, no need to move the hands to the mouse and back for anything

- integrated command line, so you can still type something like "cd \\server.domain.local\share$" and instantly have that directory in the tab (you cannot "cd" to an UNC path in cmd.exe)

- opening and working with tar, zip, rar files as if they were regular files. and with plugins you can even open disk images as if they were files

- another nice feature I totally like but which is hard to explain: you copy files simply by pressing f5 and enter. but when you press f5 a second/third time before pressing enter, the textbox selection (for the destination filename/path) switches through the full path, the filename+extension and the filename. So you can easily copy a file and change (overwrite) the filename in the destination just by pressing f5, f5, newnamehere, enter. It keeps the extension and the path you have open in the second window. True, you can do this with tab completion on the command line quite easily too, but you still have to press tab multiple times (depending on the uniqueness of the path maybe a lot more often), and you still have to type the extension by hand

- did I mention plugins? viewer-plugins (I have one that interprets ANSI sequences, for example, for vieweing those cool 90s stype BBS ads), packer plugins (I wrote a lot of these to unpack/access data files from old games), etc.

- for retro enthusiasts: PORT connection (through a parallel LapLink cable or USB data transfer cable) to another PC running Total Commander. No network necessary.

- full text search (ascii, hex, unicode) through all files (or only selected files/directories), including in archive files, with multiple patterns and excludes: alt-f7, ".c;.h|~.",alt-t, "printf" -> search for "printf" in all .c and .h files except those that start with a tilde. After the search you can send the result list to the left/right panel and work with it as if it were a regular directory. i.e. select all files that match "data." and copy them to a different directory (even though the source files are scattered throughout an entire directory tree). Of course you can also seach by metadata (only files/directories/readonly files, timestamps, limited directory depth, file size larger/smaller than X, and with the right plugins by metadata like id3/exif too ...)

Yes, for all these things there are either separate tools that do the same (maybe even better): multi-rename tools exist, opening matroshka-archives (zip in zip in tar in gz) can be done with 7zip, and there are plenty of image viewers out there that offer more features than the integrated viewer. RSync can do synchronization a bit better. but here you have it all in one place