When comparing Slate vs KWM, the Slant community recommends Slate for most people. In the question“What is the best window manager for Mac?” Slate is ranked 2nd while KWM is ranked 20th. The most important reason people chose Slate is:
Ranked in these QuestionsQuestion Ranking
Pro Extremely configurable
Pro Based on hotkeys
Hotkeys can be set to re-size and focus windows, as well as activate layout presets.
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 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 Window hints
Slate offers window hints which are an intuitive way to change window focus.
Pro Allows for tiling
Slate allows for customizing the config file in order to emulate tiling windows.
Pro Works in the same way that Xmonad & i3 does for Linux
For those who would like the same tiling window management of Xmonad and i3.
Pro Highly configurable
Using the config file (kwmrc) you can configure a variety of options including Window spacing and padding, borders, hot-key commands, etc... There are those who would say that the possibilities are limitless.
Pro Software is free and open source
Pro Windows respond very fast
Most users claim the tiling and splitting of the windows in KWM respond more quickly and more reliably than the only other known window manager of its type: Amethyst.
Pro Runs in the background
The application runs in the background. There is no indication that it is running except the automatic tiling of the windows. There is no menu bar icon or icon in the dock.
Con Project maintainance is on pause
The developer is currently taking a pause to focus on other things as of December 2015.
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 No longer being developed.
Sadly the developer has moved on to work on a different project (Chunkwm), so there will be no more updates for KWM. However the code works well; no matter what version of Mac OS X you are using.
Con Takes long to set up
You need to use the terminal and edit the configuration file in order to adjust it to the way you want. This might be a little confusing for basic users. But once you have it set, you can just copy the config file and use it on a multiple amount of machines.
Con You need HomeBrew to install it
Homebrew is required to install it. Takes more to get it work in the terminal to get it installed and working on your system.