Seems odd that people are having such different experiences with battery life. Could it be a carrier specific problem?
Welcome to April 2015. As you can see it's the same story since it was released, I just gave up trying to help, my threads and posts are all over the forums with the things I've done to my 2 S6 (1 S6 edge since April 10th, and 1 S6 Unlocked since last month) plus about 6 more S6 that I have helped set, 3 S6 edge, 2 S6 and 1 S6 active, ALL OF THEM have great battery life, not normal or regular, but Great. Today I'm receiving my S6 Active (Didn't arrive yesterday as expected) so you'll know that I'll be doing just the same.
All my Android phone have been set basically the same for the past years, all of them had their bloatware removed, same redundant Google or Samsung apps uninstalled or disabled, same Settings (Basically same Screen Brightness level, Wifi always On, bluetooth and NFC on/off when needed via Quick toggles and Location off until I need it) but with my Edge and S6 I've been even using location in power saving mode, and I still have great battery life. I even tried an LG G4 last month and returned it after 8 days, set exactly the same than my S6 edge and described above and it had worse battery life than my S6 edge by far.
So, everybody do with their phones what they want, there are people that still insist that they shouldn't do any tweaks to their phones and compare it to an iPhone, when you compare apples to apples then you can do that and compare them both, 2 different OS and both are set VERY different from factory, with Android you have basically EVERY possible option and Service on by default, running and wasting resources and mostly battery, as of now, in Android, you can't leave all that on and pretend to have a GREAT battery life unless you have a Phablet with a 3500mAh battery, with Android you should turn some things off here and there to achieve better battery life, plain and simple.
If you want your best battery life there are a lot of threads here to begin with, if you don't want to do any tweaks that's your choice also, there are also other people that have done a lot of tweaks and still have bad battery life, for those with legitimate issues, sorry, but your device should have some hardware issues, maybe radios or even bad battery (it may happens also), or as simple as bad cell phone signal, so your only option is try to get a replacement or if you are still under the 14 days go get a new one.
Again, your choice, but in my case, I'll keep enjoying my 2 S6 for now and my new S6 active after I set it today and then will decide which of the 3 I'll sell, but S6 active battery is simply a monster so I think that my Blue Topaz S6 will go very soon.