As you already know, Google celebrated Halloween last week with treats, as opposed to tricks. The treats came in the form of both hardware and software, with the LG-made Nexus 5 becoming available, along with Android 4.4 KitKat.
As far as upgrades to a mobile operating system go, 4.4 is not a huge difference, but there are noticeable changes none-the-less. Like previous versions of Android, ROM’s came out rather quickly, as did a complete system dump. The latter is important because that means APK files for download.
With these mobile executables, customers can now pick and choose from what they wish to upgrade and add the updates to their device. As Droid Life points out, “most are minor updates, but there are a couple worth looking at, like the new Google Search (it’s awesome), Launcher (“Google Home”), Keyboard, and Clock”. The blog also provides the downloads within that same post — there are 12 of them, but you can install only what you want (with the exception of the Launcher, which is explained in the post).