When comparing Notational Velocity vs Karabiner, the Slant community recommends Notational Velocity for most people. In the question“What are the best power user tools for macOS?” Notational Velocity is ranked 11th while Karabiner is ranked 29th. The most important reason people chose Notational Velocity is:
The interface is clean and unobtrusive.
Ranked in these QuestionsQuestion Ranking
Pros
Pro Simple and minimalistic
The interface is clean and unobtrusive.
Pro Free
Pro Syncs with SimpleNotes or Dropbox
Pro Low-level key bindings/mappings
For example: Fn+C now calls up contextual menus for me with:
<!-- Fn + C = same as right-click mouse -->
<item>
<name>kybd control click</name>
<identifier>private.keybd_to_control_click</identifier>
<autogen>
__KeyToKey__
KeyCode::C, ModifierFlag::FN,
KeyCode::VK_MOUSEKEY_BUTTON_RIGHT
</autogen>
</item>
Pro Make FN key into a new modifier key for custom shortcuts across apps
Cons
Con Feels a bit outdated
The last release was from 2011. Although due to its brilliant simplicity in doing what it's designed for, some might think there hasn't been any need for an update, as long as it still works with the newer OSs.
Con Difficult to configure custom actions
Configuring custom actions requires editing an XML file with very strange syntax, for which it's difficult to find good documentation.