I have 4.4 kitkat running on my Samsung Galaxy. I am impressed with the use of the new Art runtime. But certain features of the Samsung 4.1.2 stock ROM pleases me. The messaging app is good, and so is the native email app. Graphics are also better. The notification centre is also better.
I hankered so much for 4.4 that the stock Android ROM and it's stock keyboard does not please me a bit.
A way back would be to downgrade to stock Samsung ROM using kies using the emergency recovery.
Let's hope that Samsung polishes their version of 4.4.