First of all, thanks to d14b0ll0s for yet another great write up. I am one of those concerned with the battery life of the Infinity. Though some review says it got up to 9-9.5 hours with BALANCED mode I believe is the mistake. By using Power save mode, I think we can potentially get to that level but still hard.
My system is NOT rooted, but I have noticed significant change in my battery life so far with following:
1. Balanced Mode to Power Save mode.
This gets me like extra 2 hours or so. WIthout this change, 5-6 hours for my usage and with this it goes up to 7-8 hours screen time.
2. Under Wi-Fi Setting change Use wifi during sleep mode (mine is in Japanese so exact wording may be different) to never. Default setting was always. Prior to this change, I lost quite bit overnight unplugged; however, after the change it loses negligible amount.
Now rather than these, I am trying to play around with Juice Defender, which was recommended by d14b0ll0s in best application list he created. I have initially downloaded Juice Defender Free edition, and noticed may be minimal gain over #1 already instituted. But concept was great. So I ended up purchasing Ultimate edition, which allows us to control when to turn of WIFI per individual application based without Root i.e. while reading PDF I don't think I need WIFI connection.
I am still tweaking and playing with Juice Defender, but I am certain without change in #1,#2 (which are actually taken care by Juice Defender in its own way), I can gain same battery life and my hope/guess is I can get even more battery life.
So in conclusion, for those not rooted try Juice Defender (at least free version). I will let you all know how the ultimate version does in next couple days.