When comparing Slate vs SizeUp, the Slant community recommends Slate for most people. In the question“What is the best window manager for Mac?” Slate is ranked 2nd while SizeUp is ranked 9th. 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 Keyboard centric
SizeUp has user-configurable keyboard shortcuts for a set of pre-defined actions.
SizeUp is easy and simple to use without having to configure.
Pro Supports multiple monitors / spaces
Windows can be sent to different monitors and spaces. It can also be aligned as needed.
Pro Menubar dropdown for shortcuts
Learning a bunch of keyboard shortcuts right off the bat may be difficult to remember at first, which is why a menubar shortcut for the app exists with all the shortcuts listed.
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 on-the-fly split screen window settings
Unlike some other tiling window managers, SizeUp has no way to change the size of split screen actions on-the-fly. Any time a user wants to change how much room on the screen a window takes up when using the split screen function, they will need to manually change the settings, which can be time consuming.