Here is a Changelog of the 4.4.3 fixes
frequent data connection dropout fix
mm-qcamera-daemon*crash and optimization fixes
Camera focus in regular and HDR modes fixes
Power Manager display wakelock fix multiple Bluetooth fixes
fix for a random rebootapp shortcuts sometimes got removed from launcher after update
USB debugging security fix
app shortcuts security fix
Wi-Fi auto-connect fix
other camera fixes
MMS, Email/Exchange, Calendar, People/Dialer/Contacts, DSP, IPv6, VPN fixes
stuck in activation screen fix
missed call LED fix
subtitle fixes
data usage graph fix
Internet telephony fix
FCC compliance fix
miscellaneous fixes
frequent data connection dropout fix
mm-qcamera-daemon*crash and optimization fixes
Camera focus in regular and HDR modes fixes
Power Manager display wakelock fix multiple Bluetooth fixes
fix for a random rebootapp shortcuts sometimes got removed from launcher after update
USB debugging security fix
app shortcuts security fix
Wi-Fi auto-connect fix
other camera fixes
MMS, Email/Exchange, Calendar, People/Dialer/Contacts, DSP, IPv6, VPN fixes
stuck in activation screen fix
missed call LED fix
subtitle fixes
data usage graph fix
Internet telephony fix
FCC compliance fix
miscellaneous fixes