OS X Mavericks Review
OS X Mavericks (version 10.9) is the tenth major release of OS X (now named macOS), Apple Inc.'s desktop and server operating system for Macintosh computers. OS X Mavericks was announced on June 10, 2013, at WWDC 2013, and was released on October 22, 2013, as a free upgrade through the Mac App Store worldwide.
The update emphasized battery life, Finder improvements, other improvements for power users, and continued iCloud integration, as well as bringing more of Apple's iOS apps to OS X. Mavericks, which was named after the surfing location in California, was the first in the series of OS X releases named for places in Apple's home state; earlier releases used the names of big cats.
Ranked in these QuestionsQuestion Ranking
Pro Battery optimization
There are many features that improve battery life, such as App Nap.
Pro Great if you don't like El Capitan and up.
Relatively fast and retains many design decisions of the OS X of old.
Pro Memory compression features
You can have a lot of things running yet have plenty of memory left.
Pro Free if you have Snow leopard or Lion
Pro Very tweakable
There are many things you can still change through the terminal.
Pro Still supported so far
Con Outdated OS version
No longer supported by Apple (neither bugfixes or security fixes). The last release was in 2014.
Con Slower compared to previous versions
Con Very hard to find
Apple is very keen to only show the latest version.