I use it especially when moving files around in my NAS and it is awesome.
For GUI file managers, I have to say you can't get better than Dolphin. It has an integrated shell for the current directory, and you can split the view. It can also directly open ssh and SFTP URLs. For local things the combination of Dolphin and it's shell is unbeatable.
I'm partial to pcmanfm-qt, which also supports splits, and has the best "search in current directory" I've seen anywhere. You open a directory, start typing, and it filters out matching files fzf-style.
It doesn't simply select them like some other file managers do, it searches within the name and not just the prefix (again, like some other file managers), you don't have to press anything beforehand. When you get used to it, it's hard to go without it.
I used Krusader for years, then (after installing Ubuntu instead of Kubuntu) I discovered Double Commander (https://github.com/doublecmd/doublecmd), which is also free software, but more cross-platform (and developed using Free Pascal/Lazarus, which makes it old-fashioned in even more ways - it even used to be hosted on SourceForge, but it looks like they moved to GitHub now).
I just tried it now. Any way to get it to not show all of my docker volumes as disk drives above the panes? There's hardly any room for a file-manager below that.
Yeah, I noticed that too, but I have fewer docker volumes, so it didn't bother me as much. As far as I can see, you can only disable the "drive buttons" completely under Configuration/Options/Layout/Show drive buttons". If you should need it, there is also a "drives list button" which shows a menu containing all available "drives".
I miss TkDesk, which I discovered many years ago when I was first trying Linux, partly because it supports unlimited splits, not just two. In fact, if I'm remembering correctly, when navigating to a subdirectory the default was just to open it in a new split. You ended up with splits containing the full path from wherever you started to your eventual subdirectory (you could scroll the view of splits horizontally once there got to be too many).
I wish mc could browse remote URLs, and I'm tempted to author an mc clone in Go to address this particular pain-point. Maybe some day handcrafting bespoke rsync/rclone commands will frustrate me enough to motivate me.
For GUI file managers, I have to say you can't get better than Dolphin. It has an integrated shell for the current directory, and you can split the view. It can also directly open ssh and SFTP URLs. For local things the combination of Dolphin and it's shell is unbeatable.