The way Gimp looks and feels on OS X has been driving me crazy, so I’ve forced myself and found appropriate settings:

defaults write org.x.X11 wm_click_through -bool true
defaults write org.x.X11 dpi -int 75

This sanitizes window focusing and sets resolution to the value at which font sizes in Gimp seem normal.

Next I’ve changed in Edit / Preferences / Window Management tab:

  • Hint for the toolbox -> Keep above
  • Hint for other docks -> Keep above
  • Activate the focused image -> checked
  • Save window positions on exit -> checked

That’s it.