When comparing Gnome Terminal vs Terminology, the Slant community recommends Terminology for most people. In the question“What are the best terminal emulators for UNIX-like systems?” Terminology is ranked 9th while Gnome Terminal is ranked 14th. The most important reason people chose Terminology is:
Font size in Terminology automatically scales according to window size. When you resize the window, so does the text.
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 Scalable fonts
Font size in Terminology automatically scales according to window size. When you resize the window, so does the text.
Pro Looks smashing
Terminals are often very dull looks wise, not so with terminology.
Pro In-terminal video, picture and thumbnail support
Thumbnails, pictures, and videos can all be rendered in-terminal, based on the directory listing or mouse interactions. For instance, using "ls" on a picture folder will produce a list of thumbnails instead of only the filenames.
Pro Splitable
You can split windows, like in terminator.
Pro Visually customizable
It is very customizable in every aspect of the visual options.

Pro Integrates well with Enlightenment WM
Terminology is part of the Enlightenment WM packages. As such, it integrates really well with Enlightenment and other tools in the package.
Pro Block copy
You can copy text in blocks.
Pro Copyfree licensing
Terminology uses the Simplified BSD License. As it is a copyfree license, it tends to minimize license incompatibilities, legal compliance requirements, and various other complexities that may make it difficult to understand certain licenses.
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
Con Configuration is sometimes complicated and non-obvious
There's a "Settings" menu for configuration, but more options there would make it easier. Downloading themes and extensions from the official repo would be a big plus.
Con No True-Color support
Not able to display a modern full range of colors, yet.
Con Scrollback is completely nroken
Scrolling back the emulator inserts random lines from other places in the scrollback buffer in between the actuall output lines. Thus it is impossible to see a correct copy of the previous output.
Con No scrollbar
The lack of scrollbar in Terminology makes navigation difficult. But you can use keys for it.
Con Too many bells and whistles
Some people feel that Terminology has too many features that are not suited for a terminal, but for a window manager instead. For instance, viewing thumbnails, watching videos and gifs, and other similarly flashy things just feel like eye candy and should not be part of a terminal emulator.
