When comparing Slate vs Parallels Desktop, the Slant community recommends Slate for most people. In the question“What are the best power user tools for macOS?” Slate is ranked 24th while Parallels Desktop is ranked 55th. The most important reason people chose Slate is:
Ranked in these QuestionsQuestion Ranking
Pro Extremely configurable
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.
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 Based on hotkeys
Hotkeys can be set to re-size and focus windows, as well as activate layout presets.
Pro Allows for tiling
Slate allows for customizing the config file in order to emulate tiling windows.
Pro Can run Windows apps as native OS X apps
Parallels has a "Coherence View" mode that allows running Windows applications as if they were native OS X apps. In this mode Windows is virtualized in background and Windows features like Jump Lists, Taskbar, Start Menu, etc can be embedded directly within OS X.
Pro Easy to use
Parallels has an easy to learn and use UI. All important features are wizard based. It requires only a few clicks for the wizard to download and set up the latest Chrome OS, Windows or Linux build.
Pro Best integration ever
Pro Best-in-class gaming performance
Compared to other VMs, Parallels has the best gaming performance. Still, a good framerate can only be achieved with games that have very low resource requirements. A much better option for resource intensive games is dual booting Windows (via Boot Camp).
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 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.
Con Very expensive
Parallels upgrades are very expensive. Even if I bough several versions of Parallels I will switch back to free VirtualBox as they even "invented" the Pro version - mainly doubled the price you have to pay each year to have the software updated.
Con Can't import OVA files
OVA files are useful because they include all of its supporting files. Unfortunately, Parallels doesn't support these useful files.
Con Requires buying a new version of the software with each new OS X release
Chances are that the same version of Parallels won't work with different OS X releases, requiring a separate purchase of Parallels for each OS X version.
Con Home edition doesn't work with Vagrant or Docker Machine
Make sure you purchase the Pro edition (the subscription) if you need command-line access to the hypervisor.
Con Can't export OVA files
One you use parallel you get trapped into a proprietary format.
Can't share disk blocks on two unrelated virtual machines (KSM for disk) too.