When comparing Gnome Terminal vs Extraterm, the Slant community recommends Gnome Terminal for most people. In the question“What are the best terminal emulators for UNIX-like systems?” Gnome Terminal is ranked 14th while Extraterm is ranked 40th. The most important reason people chose Gnome Terminal is:
Gnome Terminal integrates well into Gnome Desktop, as well as the rest of the core Gnome Shell apps.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Good integration with other GNOME-Shell apps
Gnome Terminal integrates well into Gnome Desktop, as well as the rest of the core Gnome Shell apps.
Pro Exceptionally fast
The Gnome Terminal is usually very fast. It boots up very quickly and takes less than a second (averages to 0.25-0.59 seconds) to display files of up to 600 MB.
Pro Support for tabs
Gnome Terminal allows for the use of tabs by right clicking in the terminal window and selecting open new tab or by pressing Ctrl+Shift+t
by default.
Pro Supports scrolling
You can scroll up and down in Gnome terminal. And if you wish to do so, you can also hide the scrollbar.

Pro Solarized colors
Gnome Terminal comes with a solarized colorscheme installed and ready to use.
Pro Content re-flow when window is resized
When using the GNOME Terminal, if you have long lines of text inside it and then you change the window, the text will also automatically update according to the new window size.
Pro Notifications upon command completion
This isn't in the current release but in development versions you get notifications when commands are complete. This is great for long-running commands, relieving you from continuously checking to see if your command is done.
Pro Configurable keybindings
Configurable key bindings can be used for copy-paste, sending SIGINT, switching tabs, and so on.
Pro Transparency
We can change the alpha canal and see through the terminal.
Pro Open Source
Pro Drop-down support
Drop-down functionality can be added to Gnome Terminal via an extension.
Pro Clever memory management
Multiple terminals are managed from one gnome-terminal instance that takes up about 45 MB. Adding on other instances (with 10k lines of used buffer), each terminal requires about 16 MB of memory.
Pro Getting better and better over time
Tilix used to surpass gnome-terminal but right now they are both the best options unless you have special needs.
Pro speed
not the fastest ever, but for me its a good comprimise of features vs performance
Pro Cross platform
Pro Supports tab, splits and panes
You can set up your own layout with multiple splits and tabs.
Pro Shell integration
The shell integration makes it possible to group in command output in "frames" which show success/failure.
Pro Image support
You can view images and other data types like audio directly in the terminal.
Pro Keyboard based text selection
It is possible to go into a cursor mode where you can select text just like in a text editor. It even supports multiple cursors.
Pro Global shortcuts
You can configure global shortcuts to open the terminal.
Pro Keyboard friendly "Command Palette"
Just like Sublime, Atom and VSCode you can easily search and find commands from the drop down Command Palette.
Cons
Con No background transparency
While this used to be a good option, background transparency has been removed.
Con Gnome library dependencies
While not an issue if using Gnome, when trying to use this terminal in other desktop environments or window managers there will be a large amount of dependencies tied to the app making for a large install size. For those trying to keep their desktop lean this may be an issue.
Con Font rendering doesn't look good
it seems that everything is fatter per default.
Con Heavyweight
To achieve a large amount of speed, Gnome Terminal has to use a relatively large amount of memory to run. It may eat up to 15-30 MB per instance, depending on the task it's doing.
Con No tab names
Since Gnome 3, the feature for manual renaming of tabs was reaped off.
Con Doesn't support font ligature still in 2019
gnome-terminal uses vte for its terminal emulator, and vte simply doesn't support font ligature (yes, it's 2019). This is what its maintainer thinks about it.
He really thinks supporting font ligature breaks terminal's grid, like he doesn't understand a font that's monospace is a monospace no matter if it has ligature or not.
Con Incomplete vt handling due to using libvte
Con Restrictive license
