In this post, I lamented on the incredible slowdown seen when expanding many compressed files in Finder. To save a trip back to that article, here's the tldr; version:
|Expand 24 .gz files
|Terminal is 984.6x faster than Finder
With a bit of work, though, you can harness the power of Unix in Finder, and get both the GUI and the speed when expanding files. There are many ways to do this, including third-party apps such as The Unarchiver. You could also write an Automator Service to do the work for you. But I chose to write a Keyboard Maestro macro, because I could make the macro a menu bar option that only shows when Finder is frontmost:
As seen, I actually have two expanders, one that expands just the Apple sales reports mentioned in my original post, and the other that will handle any mix of compressed files. (Yes, the 'all files' macro could also handle the Apple sales reports, but because of how it has to run for multiple file types, it's marginally slower than the dedicated macro.)
These macros both work in the same way—they call on Unix apps to do the expansion, bypassing Apple's slow GUI expander (which is called Archive Utility). If you're curious how they work, and/or would like to download them for your own use, keep reading.