4 Reasons Not to Install macOS High Sierra 10.13.5 & 10 Reasons You Should

Install for Apple File System

The macOS High Sierra update converts your mac to the Apple File System if you are using a SSD. This means MacBooks, MacBook Air and most MacBook Pro models will switch, as will a good number of iMac and Mac Pro devices. 

With the Apple File system you will be ready to use the SSD to the full potential. Apple specifically calls out the responsiveness of using your Mac with this new format saying it will, "make common tasks like duplicating a file and finding the size of a folder’s contents happen instantly."

The new system also includes built-in encryption, crash-safe protections and simplifies data backup. This is a new system, designed with new Macs in mind, but you get many of these benefits on your current Mac -- as long as you have flash storage.