When comparing Terminology vs Alacritty, the Slant community recommends Alacritty for most people. In the question“What are the best terminal emulators for UNIX-like systems?” Alacritty is ranked 7th while Terminology is ranked 9th. The most important reason people chose Alacritty is:
Written in Rust with a philosophy focusing on speed and simplicity, Alacritty is one of the fastest terminal emulators out there.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
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.
Pro Blazing fast rendering with GPU-accelerated
Written in Rust with a philosophy focusing on speed and simplicity, Alacritty is one of the fastest terminal emulators out there.
Pro Looks good
Alacritty looks very slick on Linux, especially with GNOME or i3.
Pro Simple configuration
The configuration file is very well made and easy to use. You can fine tune your preferences to perfection in a matter of minutes.
Pro Comprehensive font options
Alacritty can be configured to adjust line spacing (height), letter spacing (width), and individual character horizontal/vertical positions.
Pro Has support for image previews in w3m and ranger
Pro Has text ref-low when window is resized
Pro Fast and simple but with true color support
It's simple and fast like xterm or urxvt but with truecolor support which is a big plus if you use a terminal based code editor. Basically Alacritty has all the features you need and nothing you don't (if you're using tmux for multiplexing).
Cons
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.
Con Cannot into ligatures
Alacritty does not support ligatures in Fira Code, Iosevka etc.
Con Unreliable Font Rendering
Like a box of chocolate you never know what you're going to get.
Con Sacrifices basic features for raw performance
The Suzuki GSXR of terminals. Or your ditzy, blonde high school cheerleader; fast and pretty but not a lot going on under the hood.
Eschews a negative developmental philosophy towards including said functionality, with the official reason cited in project documentation as "Not within the realm of a terminal emulator" and ostensibly, "best left up to other tools such as terminal multiplexers" [such as screen or tmux]. Which is unfortunate when you factor in speed against terminal with the functionality built in vs their reliance on 3rd party tools:
tmux on alacritty: 'find /usr' time: 3.234s, cpu: 72%
tmux on konsole: find /usr' time: 1.777s, cpu: 96%
See issue here.
