When comparing iTerm2 vs Slate, the Slant community recommends iTerm2 for most people. In the question“What are the best power user tools for macOS?” iTerm2 is ranked 1st while Slate is ranked 21st. The most important reason people chose iTerm2 is:
Other than being able to customize the various shortcuts, iTerm2 also lets you customize the colorscheme, font, transparency, etc.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Extremely customizable
Other than being able to customize the various shortcuts, iTerm2 also lets you customize the colorscheme, font, transparency, etc.
Pro Autocomplete is built-in
iTerm has autocomplete features built in. It remembers your past commands and when you are writing something on the terminal, simply pressing Control-;
it will show you a drop down menu of suggestions from which to choose.
Pro Complete out of the box
Unlike most terminal emulators, iTerm2 comes with a pretty complete set of features. It has built-in search, autocompletion, tabbed navigation, Growl support and even a built-in clipboard manager for various API keys and such.
Pro Fine tuning for fonts
It's possible to choose a font and adjust vertical and horizontal spacing.
Pro Can immediately open files inside a text editor
You can Ctrl+Click on a file path to open said file in a text editor.
Pro Supports mouse actions
Has support for mouse actions like clicking, dragging, selecting, etc.
Pro Active maintainers
Issues resolved fast by quality contributors.

Pro Works well with powerline fonts
Pro Completely free and open source
iTerm2 is completely free and open source. It's released under the GPLv2 license.
Pro Split panes
Easy to split panes to either horizontal or vertical sections. Makes it easy to observe multiple console windows.
Pro Supported by many applications as a terminal app selection
If an application has terminal integration, there is high probability it allows iTerm2 to be selected.
Pro Intuitive
Pro Cmd+Shift+I to Input all
Wanna SSH your server from multiple tabs, here you go.
Pro You only need to type in commands once
iTerm2 can store up to 4M of history of commands you already used. This, coupled with the built-in search features makes it possible to type a command only once and then search for it through the history for subsequent uses.
Pro Works perfect with Oh My Zsh
It's a perfect base to add Oh My Zsh on top of it and enjoy a lot of themes and a really pleasant look and feel.
Pro Works well with tmux
The great mouse and clipboard support that are built-in go really well with tmux.
Pro Any key can be mapped to any function
Using the Preferences Menu you can set up hotkeys to map virtually any action you can think of to a single key or a combination of them. This is extremely helpful as it allows you to use shortcuts to edit commands you are typing in the terminal and while most terminal emulators have shortcuts for this sort of thing, few of them let you define your own.
Pro GPU-rendered, blazing fast and super smooth
Many people say they use Kitty or Alacritty because they are GPU-rendered. That was true a long time ago. But iTerm2 has been GPU rendered for years now. It's so fast and smooth that you soon forget you are in a terminal.
Pro Beautiful, minimalistic and elegant UI
It's super-clean and during use it gets completely out of the way, it's a beautiful canvas for your terminal work, a pure joy that never gets old.
Pro Can be configured as a drop-down terminal
Can be configured to work as a drop down terminal like Quake.
Pro Cmd+D to split plane vertically
Very handy to use multi-tab.
Pro Extremely configurable
Slate is similar to Linux WMs like Xmonad in that it is nearly infinitely configurable. You can either use the default configuration file or just Javascript for very complex/dynamic settings. Slate also offers editing a ".js" or a ".slate" file for configuration.
Pro Based on hotkeys
Hotkeys can be set to re-size and focus windows, as well as activate layout presets.
Pro It's free
Slate is completely free to download and use, which is a great option in a field of Mac WMs that often costs money to use.
Pro Allows for tiling
Slate allows for customizing the config file in order to emulate tiling windows.
Pro Lets you set default layouts
By using a feature called "snapshots", users can set up different default window layouts in Slate that they can switch to and from on the fly.
Pro Window hints
Slate offers window hints which are an intuitive way to change window focus.
Cons
Con Keycodes are not passed through following Linux standards
If you come from a Linux terminal emulator (Gnome Terminal, Konsole...) and you rely on key-combos that are widely supported in those, porting the same functionality to iTerm is possible but will require a lot of research and configuration on your part, so account for a long painful adoption period.
Con Not quite as fast as Alacritty or Kitty
Comparing these 3 terminals on the same machine/config, iTerm stands out as the slowest of the bunch. The difference may not be noticeable to all users.
Con Way too many menu items and settings
Finding the right one is like searching for a needle in a haystack.
Con Doesn't support Snow Leopard 10.6.8
Some people still use Snow Leopard or other 32-bit systems.
Con Doesn't support RTL
Con Project is no longer in development
Development is no longer active on this project as of 2017.
Con Hard to configure
There's no graphical user interface for configuring Slate, meaning it has to be done from the command line interface or by editing a config file. This makes it somewhat difficult and time-consuming.
Con Missing features
Unable to perform all tasks of software it was meant to replace.
Can not move windows between 'Spaces' (virtual desktops).
Con Video fail
Demonstration video failed to highlight any of the advantages of the windowing system. Or at least, the advantages were so subtly intrinsic that no-one who didn't already use the system could appreciate them.
