I have updated to 4.3 by following the link below.
http://www.youtube.com/watch?v=r1iYdjtIjq0
GSM unlock works with this update. New icons, lot of new things. Will update in next post.
If you are in custom recovery, download stock recovery (recovey.img) from the link below
http://forum.xda-developers.com/showthread.php?p=40850611
Use this recovery.img to flash using mobile odin lite from play store.
Remember the update has to be placed in the external sd card.
Use stock recovery, install update from external sd card, flash. Will take around 20 mins.
IMPORTANT
if you have any MODS installed, please uninstall it then flash MF9 firmware and only then update to MJA.
Sent from my SPH-L720 using Tapatalk