When comparing tig vs GitHub Desktop, the Slant community recommends tig for most people. In the question“What are the best Git clients for Windows?” tig is ranked 4th while GitHub Desktop is ranked 16th. The most important reason people chose tig is:
If you prefer to do most of your development inside the terminal, changing windows to move to a GUI git client can be annoying. Since tig runs inside the terminal, that's avoided.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Allows you to stay in the terminal
If you prefer to do most of your development inside the terminal, changing windows to move to a GUI git client can be annoying. Since tig runs inside the terminal, that's avoided.
Pro Fast
Pro Vim-like bindings
Pro Available in Homebrew
Can easily be installed with homebrew simply by running brew install tig
Pro Works on any platform
Pro Great GitHub integration
This is the official GitHub desktop client built by the GitHub team.
Pro Simple, streamlined GUI
GitHub Desktop uses an extremely simplistic two-panel view. It's not capable of complex historical visualisations like other GUIs, but it is very easy to use (especially for git novices).
Pro Supports pull requests
In addition to being able to seamlessly and easily integrate with all of GitHub's features, it also supports forking and submitting pull requests on any open source project hosted on GitHub.
Cons
Con Steeper barrier to entry as compared to a GUI solution
Since you have to get used to working in the terminal (if you are not already used to doing that) and learn the commands, it has a steeper learning curve than GUI clients which are usually more intuitive and easier to grasp.
Con Limited
Can't handle complex tasks. The Help Manual advises to use command-line Git instead.
Con Does not support multiple Remotes for a repo
Only allowed to assign one URL as remote. To manage/sync/fetch other remotes, use command-line Git instead.
Con Overly Simplified UI
UI that is designed not to support the needs of power and enterprise users. Management of more than five repos is next to impossible.
Con Buggy
Poster child for authors' programming ideology (FRP), likely the cause for the odd quirks and bugs it has.

Con Not free/libre
This application is proprietary, and thus cannot be modified or freely distributed.
Con No Linux support
There's no Linux version of this client.
Con Non-GitHub repositories are not fully supported
Since this is mainly a GitHub client, other repositories are not fully supported and with as many features and setting up a repo hosted anywhere else but GitHub is troublesome.
