Most of you are getting better battery life then I've ever gotten, LP or KK. 12 hours at 49%? I would kill for that.
I'm in the same camp as you but I've never gotten great battery life with any phone. It's most likely in my case due to several things.
First, 4G signal both at home and at work. Poor signal will suck the life out of a battery as the towers ping the phone and the phone tries to reach the tower over and over just to maintain a good connection.
Second, signal level is directly proportional to transmission speed, and then speed of communication is directly proportional to power consumption. It takes essentially the same transmission power (milliwatts of transmission power), to send data slower (smaller packets), as it does to send faster, but of course it will take less time at faster speeds and so will ultimately use less power to send the same amount of data with a stronger signal.
Third, I tend to have a lot of things running such as social networking, several email accounts from different providers and a myriad of other tools, such as Android Wear, AppLocker, App Redirect, Chrome to Phone, Facebook, Facebook Messenger, Fit, Google Drive (for pic syncing), Google Hangouts, GrooVe IP Lite (VoIP), Instagram, KIK, Meetup, Yahoo Messenger, Omni Swipe, Skype, Snapchat, Tapatalk, TextFree, Tumbler, WhatsApp, Yolify, and YouMail. Most people don't run so much stuff and believe me, I use them.
Forth and certainly high on the list of power sucking is the screen on time (SOT). Right now I'm at 67% with SOT of 1:17, using 24% of power consumed so far. Android system is a close second at 22%, Email at 13%and Google Play Services at 12%...
You'll see below how power consumption is related to signal strength as well as how system awake time is the second biggest contributor to battery consumption.
So it's a specific user's profile that I believe has the greatest overall impact to battery consumption.