None that I can really sound off about. I'm thinking KitKat is more under the hood w/ some slight visual changes. I welcome the change in icons after a seeing Holo Blue for a while.
I am just looking at a large sample. 4.4.2. is mainly a bug squisher and performance improvements. I had wanted to see if anyone noticed any differences at all.
I personally haven't noticed any difference in performance, nope. I don't know what KitKat was meant to improve. If anything, the battery is worse when used frequently although standby time is exactly the same.
Galaxy S4 Octa here, so far I noticed a snappier UI and more RAM available at any given time compared to 4.2.2 and 4.3.
Screen also got a touch of improvement, it looks sharper and more vivid, other than that not much else.
As smooth as my Verizon G'Note3 is performing with JellyBean, it makes me wonder if its worth updating to KitKat when Verizon finally releases it...things that make you go ....Hummmm
Haven't noticed a damn thing with my AT&T S4 except for standby battery time improving over 4.3 for me. I swear to you all I could unplug my phone from the charger and let it sit and it would be dead in 4 hrs...that's with no apps running or even mobile data turned on. Basically everything was turned off. Now when I go into sleep mode it kind of freezes the battery where it's at. Still drains like a storm pipe whenever I'm using it though
i did notice significant improvements on my Moto G!
i'm on the runtime ART and the phone seems a bit smoother and faster than before! also i found Chrome to be a lot better on 4.4.2...when i had 4.3 it was rly laggy but now it's rly smooth!
camera improved a lot too and now it's pretty decent and i think it now follows the phone standards!
battery life has improved for me, i easily get 1day+ on moderate use!
aaand that's the most significant improvements i noticed!
maybe those with a 2Gb RAM won't rly feel any performance difference because Kitkat optimizations were more aimed to devices with low RAM! so i guess pplz with 512Mb - 1Gb RAM will feel it the most! (if any 512Mb phone gets Kitkat lol which was Google intention, that even older phones can get the most recent updates)