When comparing Dolphin vs Ranger NCurses file manager with Vim bindings, the Slant community recommends Dolphin for most people. In the question“What are the best GUI file managers for UNIX-like systems?” Dolphin is ranked 3rd while Ranger NCurses file manager with Vim bindings is ranked 14th. The most important reason people chose Dolphin is:
As with any KDE app, Dolphin, allows adding or modifying toolbar buttons and keyboard shortcuts.
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Pros
Pro Immenseley configurable
As with any KDE app, Dolphin, allows adding or modifying toolbar buttons and keyboard shortcuts.
Pro Can split views
Dolphin supports splitting the view in two navigational areas, this way you can navigate two different directories at the same time.
Pro Integrated terminal
Pressing F4 with any opened folder on a mounted path opens a console within dolphin.
Pro Also has a refresh option
Dolphin is without a doubt the best fully functional and easy to use and multitask with.
Dolphin also has a refresh button which no other File manager has. It's great for tracking a large files transfer; that's what file managers are for - good common sense.
Pro Easy to extend with plugins
Dolphin follows KDE's philosophy of being extendable and configurable. It can easily be configured and customized through plugins.
Pro Auto mounts flash drives
Dolphin automatically identifies and mounts external flash drives.
Pro Fast at opening graphics folders
Pictures with or without previews is optional and selectable at the touch of a button.
Pro Does not use third party libraries
Unlike all those GTK-based file managers it does not have to rely on external written software for its functionality because KF5 is KDE SOftware and developed alongside.
Pro Keeps its state
It starts with last opened folders.

Pro Fully supports HiDPI
Supports HiDPI displays.
Pro Automatically centers items
In icons view mode, the space between files gets stretched so that there is never and annoying empty space at the right side of the window.
Pro Fast response
This is a NCurses GUI so it is a command line program with a user interface of shortcut keys which allows for a fast response.
Pro Detailed previews
The program will give previews in the terminal with detailed information concerning the file.
Pro Bookmark system
Makes it easy to jump to any specific folder locations you work with.
Pro Extremly minimal GUI interface
Cons
Con May be a little slow on startup
Dolphin can be a little slow on startup (depending on distro, hardware etc...). Startup time can vary from a couple of seconds to up to a minute.
Con Can hang on remote file systems
It doesn't cope well with remote file system nicely like sshfs or any samba, like when network is not responding/very slow. It just hangs.
Con "Type" column too verbose
Despite having a large enough monitor, if you keep the size of the browser window small, the "Type" column (in "Details" view mode) insists on including the complete multipart MIME string, making the column so wide that trying to limit its width makes the column useless. Sorting by "Type" renders the list into an incomprehensible mess.
Con Poor optimization on later versions
Con Too simple
Feels weird on KDE because it has less customizing options Konqueror and any other KDE app have.
Con Can't perform ROOT actions
Developers set a constraint in Dolphin that deny Dolphin to run with root permissions. Hence, if you want to perform an action that require root permissions, such as rename a file in /etc/ folder, you are forced to use terminal or switch to another file manager.
Con Steep learning curve for people who are not used to Vim
Since it uses many of vim's keybindings, it may be hard for someone who does not use vim or does not know how to use vim to learn how to work with this file manager.
Con Extremly minimal GUI interface
Almost everything is a shortcut key. Using ? is essential to learning this program. To show hidden files it is z-h.
