Well, after witnessing incredible battery life on latest HebMIUI (mostly taken from Pimp My ROM and Adrenaline Injector), I decided to make a flashable for the rest of the ICS ROMs we have here.
I must say I also use the LB6 modem which is known to give good battery life, so you are advised to install it too, but, it's your call.
I also add here AutomateIt app, which lets you decide what the device will do for certain events (open/close wifi/3G/4G/screen/charge etc.) which you can utilize to save battery life.
links to modem & sources:
SGH-T959W LB6 modem
I take no responsibility for any damage claimed.
Tested on MIUI, AOKP.
Make a nandroid backup and flash it via CWM/TWRP.
Let it soak in for 1-2 days and let me know what you think.