When comparing Slate vs TextWrangler, the Slant community recommends Slate for most people. In the question“What are the best power user tools for macOS?” Slate is ranked 21st while TextWrangler is ranked 58th. 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 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 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 Fast to start up
It starts up fast because is not bloated. It has all the essentials of a text editor.
Free but capable alternative to BBEdit.
Pro Built-in FTP/STFP browser
Edit remote files easily.
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Con No Longer Maintained
Bare Bones, the developers of TextWranger, recently ended maintenance and support for the product. Per the Bare Bones website (https://www.barebones.com/products/textwrangler/): "We have sunsetted TextWrangler, and we encourage anyone interested in TextWrangler to download and use BBEdit instead."
Con Not Compatible with macOS High Sierra (10.13+)
Per the Bare Bones website (https://www.barebones.com/support/new-os.html): "TextWrangler is not compatible with High Sierra. We suggest that you use BBEdit as an alternative . . . ." Since Bare Bones officially sunsetted the product, it will unlikely be compatible with subsequent macOS release versions either.