When comparing Slate vs Mosaic, the Slant community recommends Slate for most people. In the question“What is the best window manager for Mac?” Slate is ranked 1st while Mosaic is ranked 12th. 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 It's slick, quick, and does the trick…
Mosaic is probably the best window manager I have ever used for Mac. There are so many options available, you're sure to be able to set it up to suit your workflow… and the Mosaic Remote app gives Touchbar like control, without a Touchbar!
Pro Stays out of the way
While still allowing for insane customization.
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.