Things I've noticed:
- The icons in the Finder window toolbars wiggle when you customise the toolbar. Cute.
- You can no longer "Get Info" on items in a Finder window's sidebar, for some unknown, and annoying reason.
- Shadows around windows are much lighter than in High Sierra. In dark mode, this means windows are quite 'flat'.
- You *still* cannot alter the size of the font in a Finder window's path bar, status bar or tab bar.
- There's a new option in the Finder's View menu to "Use Group View", and you can then change how the files are grouped. I think this replaces "Arrange By".
- Finder's preferences allow you to "keep folders on top: "In windows when sorting by name" and "On Desktop". This was limited to "by name" in High Sierra.
- With the new "accent colours" in System Preferences > General, the colours do not include the original "Blue" option, but "Graphite" is there.
- If you don't use dark mode, you can now no longer "use dark menu bar and Dock". So, if you like light windows and dark menu bar and Dock, you're out of luck in Mojave

- Dark mode only applies to window 'chrome', so if you've set a background colour for a specific window, it is maintained across light and dark modes. That might look good for some combinations, but whilst a light grey in light mode looks good, it looks terrible in dark mode. I kinda think the windows should store two sets of appearance settings, one for light mode, one for dark mode. If not, you're going to have to change your window colours everywhere
