what are the most notable differences between KK & JB?

[HootLife]

I recently upgraded from a Samsung Rush running Jelly Bean to an LG Tribute with Kit Kat. I've noticed a couple of differences, and the ones that I've noticed lead me to believe that there's more cool stuff that I'm missing out on.
So, what's new (to some of us)?

 

[B. Diddy]

Welcome to Android Central! The main differences I can think of off the top of my head:

1. Priority Notifications. This isn't necessarily a good thing, as it took away the ability to simply mute the phone. You have to either decrease the notification volume to Vibrate, or select No Notifications. But sometimes people still want silent notifications, and just don't want the phone making sound or vibrating.

2. White backgrounds for system settings menus, App Drawer, and homescreen folders. Also not universally popular--it can be a little blinding if you're using the device in a dark room.

3. Smart Lock. Very cool, allows you to bypass the screen unlock if the phone is paired to a trusted device (like a Bluetooth headphone or a smartwatch), or if it's in a trusted location that you set.

4. No lockscreen widgets--replaced by lockscreen notifications. Also somewhat controversial. Lockscreen notifications can act like widgets (like the Play Music lockscreen notification), but they're generally smaller than the old lockscreen widgets, and can be a little more involved to use.

Someone else chime in if I forgot anything major.

 

[LR G]

So, what's new (to some of us)?

Beautiful & Immersive
A more polished design, improved performance, and new features.​

Just say “Ok Google”
You don’t need to touch the screen to get things done. When on your home screen* or in Google Now, just say “Ok Google” to launch voice search, send a text, get directions or even play a song.

A work of art
While listening to music on your device, or while projecting movies to Chromecast, you’ll see beautiful full-screen album and movie art when your device is locked. You can play, pause, or seek to a specific moment.

Immerse yourself
The book you're reading, the game you're playing, or the movie you're watching — now all of these take center stage with the new immersive mode, which automatically hides everything except what you really want to see. Just swipe the edge of the screen to bring back your status bar and navigation buttons.

Faster multitasking
Android 4.4 takes system performance to an all-time high by optimizing memory and improving your touchscreen so that it responds faster and more accurately than ever before. This means that you can listen to music while browsing the web, or race down the highway with the latest hit game, all without a hitch.

Smart & Simple
Google smarts improve every corner of the Android experience.​

The future is calling
The new phone app automatically prioritizes your contacts based on the people you talk to the most. You can also search for nearby places and businesses, your contacts, or people in your Google Apps domain.

A smarter caller ID
Whenever you get a call from a phone number not in your contacts, your phone will look for matches from businesses with a local listing on Google Maps.

All your messages in the same place
Never miss a message, no matter how your friend sends it. With the new Hangouts app, all of your SMS and MMS messages are together in the same app, alongside your other conversations and video calls. And with the new Hangouts, you can even share your location and send animated GIFs.

Emoji everywhere
Sometimes words can’t express how you feel. For that, there’s Emoji, the colorful Japanese characters, now available on Google Keyboard.

Grab & Go
New features help you get things done while you’re on the move.​

Print wherever, whenever
Now you can print photos, documents, and web pages from your phone or tablet. You can print to any printer connected to Google Cloud Print, to HP ePrint printers, and to other printers that have apps in the Google Play Store.

Pick a file, any file
From apps like Quickoffice, you can open and save files on Google Drive, other cloud storage services, or your device. And with quick access to recently used files, it's easier than ever to send the file you were just working on.

Your office, anywhere
Create and edit documents, spreadsheets and presentations from your phone or tablet with the newly redesigned Quickoffice

Source: http://www.android.com/versions/kit-kat-4-4/​

 

[treetopsranch]

But the biggest con or bad is that KitKat took the ability to save stuff easily to the external SD card away! That's a big deal for us business users that want to save spreadsheet and word stuff to the external card. And don't tell me it can be done with the stock file manager. I'm talking about apps not being able to save to the external card. I am using a Samsung Note Pro 12.2, a beautiful tablet.

 

[B. Diddy]

Yes, but there were security reasons behind that move: KitKat and SD cards — what's fixed, what's broken and what's misunderstood | Android Central.