Every now and again I go to Android 4.3
, Google Special Edition's leaked firmware, I9505GUEUBMFP
I use the DjeMBeY GT-I9505 GOOGLE Special Edition ROM - CWM/TWRP/PhilZ flashable ZIP: v3
which is pure stock. Downloads and step-by-step installation instructions are in the DjeMBeY ROM's i9505 - Dummies Guide
There are no Samsung apps or modifications with this firmware which is as close as you can get to the pure Android 4.3
If you like a cut down firmware with no frills then this is one for you. It also means that you can try out Android 4.3
features right now.
Google Android 4.3 is here, and it tastes like Jelly Bean
Google releases two new dev videos for Android 4.3
Here are some screenshots...
Home screen with Nova Launcher, (APEX doesn't work on 4.3 yet and the basic launcher was not enough for me).
Contacts (now called People)
Camera settings 1
Camera settings 2
For more details and installation instructions, see DjeMBeY ROM's i9505 - Dummies Guide
xda thread, here