Here are some of my impressions.
1. Like having 5 icons on the lock screens instead of 4 icons.
2. No swipe to capture screen shot of the lock screen.
3. Voice commands to take a picture more responsive.
4. Like choice to save pictures to micro sd card or the phone.
5. Like home screen mode and blocking mode.
6. Like nightshade with the time, date, and and day of week.
7. Use airplane mode and WiFi instead of being able to toggle no data not as good but is a workaround.
8. Like having quick access to Settings on nightshade.
9. Pinch to zoom and double tap screen gestures in browser smoother and more responsive.
10. Webpages seem to load faster. Had to reboot twice after the update as browser seemed to hang and not load quickly.
11. Smart Stay seems to work better in both low and normal light conditions.
12. Swiping between home screens is faster and smoother.
13. SwiftKey works well and was not affected by the upgrade.
14. Apps, widgets and downloads have tabs. Longpress widget to put on a homescreen and resizing is good.
15. Like longpress home button to get task manager, Google and remove apps.
16. Would have liked split screen for true multi - tasking.
17. Battery life is only marginally better.
18. Kapersky anti-virus seems to scan faster.
Sent From My Samsung Galaxy Note 10.1 Tablet