Fair enough, but if one is getting good battery results, what does it matter? Another hour out of your phone over a 36 hour period? I don't know, I'm just thumb sucking a figure here. I used to fret about battery life. I eventually took away the "show battery percentage" setting in JB as I would find myself always looking there first when switching the screen on. Always trying to work out how much has been used since the last time, oh no, 1% extra this hour than last hour, what went wrong, find the spook in the system, yet the whole time I was getting a good battery life (in fact, more than double the life I was getting out of my S2) and was very satisfied overall.
I have definitely found little custom mods played a big impact on my battery life. There was a battery indicator mod, changing it to percentage with your own custom set of images. If I flashed that mod to the phone, battery life was killed. If I "Froze" certain apps, battery life would suffer (almost as if there were links to other active apps, that tried to search for the frozen ones).
I eventually got over my battery life obsession, uninstalled Tasker, LLama and all those other kind of apps, I leave my wifi on, bluetooth on (connecting to my car kit), screen on auto brightness, Nova launcher is my default launcher, Friendcaster with push notifications, selected frozen apps and I do stick it into airplane mode when closing my eyes at night and back to full when waking up in the morning as the alarm goes off. Average battery life is 36 hours and no stressing about whether it's 35 hours today but it was 37 hours yesterday.