Using Ressurection Remix 3.1.3, though most of the benefits for battery probably come from using the Dorimanx kernel. Not sure if you could chuck that on Cyanogenmod... Though I've used their kernel on my ROM and I agree the battery life was lacking.
What ROM is that on.. I have been using cyanogenmod for a while and battery life is the only thing that is letting it down.
It doesn't on my S2, actually getting significantly better battery life on 4.2.1 than on Gingerbread despite the battery being more than a year older.
Loving the S3, but is it me, or does Google Now really eat up the battery?