Commander One is kinda barebones, QSpace looks like Finder plus some bonus stuff. Compared to godly Total Commander (on windows), everything else is very shallow. Double Commander tried to replicate it, and kinda succeeded, to an extent. It's not about big shiny features, it's about all the small nitpicks you do regularly.
Example:
move file panel cursor on a file (as example, big text file), press F3 to open it. Built-in preview opens first page very fast even if file is 1GB+, by not loading anything except the first page ;) scrolling also works without visual lag even on slow HDD. Now press ESC and focus is back on a window you came from and can continue navigation.
Something as simple as focus thing is regularly broken on oh so many file managers
Example: move file panel cursor on a file (as example, big text file), press F3 to open it. Built-in preview opens first page very fast even if file is 1GB+, by not loading anything except the first page ;) scrolling also works without visual lag even on slow HDD. Now press ESC and focus is back on a window you came from and can continue navigation.
Something as simple as focus thing is regularly broken on oh so many file managers