While everything you said about usage habits is true, I still think that "many" of the people getting 4-6 hours are experiencing some kind of problem unrelated to their habits. I have had the iPhone 3G, 4, and now 5, all while living in the same area, Hiroshima City, where signal strength has greatly improved over the last 5 years.
I had fantastic battery life with my 3G and 4, but I average about 3-5 hours with my iPhone 5. We do have LTE in Hiroshima City but I have it turned off. Bluetooth is off, mail set to manual, brightness at 30%, almost zero gaming (most of my iOS gaming is now done on my iPad for fear of draining my iPhone battery). I browse the internet normally, and possibly slightly more than with past phones due to the faster speed of the current phone. But even so, when I check my cellular data usage, it is waaaaayyyyyy more than it should be. Something is definitely going on behind the scenes, and I'm not the only one this is happening to.
I've tried DFU restores, turning off iCloud, setting up as new, and all of the other tricks, but nothing helps. I am on my third iPhone 5 and nothing has changed. I'm gonna wait for the next iOS update in hopes that it'll help, otherwise I'll just keep returning it until I get one I'm satisfied with.