When comparing Gitg vs GitHub Desktop, the Slant community recommends Gitg for most people. In the question“What are the best visual git GUIs?” Gitg is ranked 12th while GitHub Desktop is ranked 14th.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Client side decoration (CSD)
Pro Beautiful and simple
The UI is very straightforward, once you open it, you can browse your computer to find an existing git repository and open it in the app. Once opened you can browse commits and view remotes immediately. It also allows you to browse the files and preview them.
There's also a commit view which shows past commit messages, as well as unstaged and untracked commits.
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 Some git features are missing
There are some key/authentication issues.
Con Slow on large repositories
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.