I wanted to manually sync specific music albums from my media server to my laptop and wondered which graphical tool I could use (except the file manager). Then I used the application I already use to solve git merge conflicts: Meld.
Two things were necessary for meld to be useful for my task:
- Enable Preferences > Folder Comparisons > Compare files based only on size and timestamp, otherwise meld would compare the files byte by byte
- After the directories had been compared, every folder was expanded, which was too convoluted. Right-click the main folder and select Collapse Recursively