When comparing PCManFM vs Dolphin, the Slant community recommends Dolphin for most people. In the question“What are the best file managers for UNIX-like systems?” Dolphin is ranked 3rd while PCManFM is ranked 10th. The most important reason people chose Dolphin is:
As with any KDE app, Dolphin, allows adding or modifying toolbar buttons and keyboard shortcuts.
Ranked in these QuestionsQuestion Ranking
Pros
Pro Lightweight
General use, and most operations, are snappy and responsive.
Pro Simple
PCManFM is a very lightweight and simple file manager.
Pro Can open folder as root
PCManFM can open different folders as root, this way you don't have to use the terminal to move around files for which you need root permission.
Pro Auto mounts drives
PCmanFM automatically detects and mounts available drives.
Pro Supports "quick-directory" typing
While in a PCManFM window, typing either a "~" or a "/" will automatically start typing into the location bar, allows for tab completion, and pressing Enter goes straight to the typed directory.
Pro More RAM is available for other processes, and the system uses less swap
Overall, the system becomes faster.
Pro Uses tabs instead of new windows
Tabs can practically be managed just as in a browser, so you don't end up with windows open all over your desktop. New tabs automatically start in the same location.
Pro Fastest starup
PCmanFM is the fastest GUI file manager to start.
Pro No back seat driver
Does not obstruct professional work by engrossing root warnings.
Pro Compact
Supports fast failure resolving in bulky configuration and log folders.
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.
Cons
Con Can't extend with scripts
Unlike Nautilus and Caja, this can't extend with scripts. If script extension is added it can become a really good FM.
Con Some operations are slow
Because it tries to be as lightweight as possible and tries to use very little RAM. This can unfortunately lead to it being slow sometimes.
Con Right-click option choice limitation
You can only choose one option in the right-click menu instead of being able to select multiple at once.
Con Uses a bit more RAM than thunar
Thunar uses less RAM but you pay in slower startup and stability.
Con Directory trees can be confusing
Starts you off in a directory tree that is your home folder as if that is the very top. (Just use a single tree as it actually is and expand appropriately).
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.