Most likely the reason that it can't make it through a day without a charge is because of 4G/LTE. If battery life is that important, you can force your phone to only use 3G and you will see much greater life.
(but I do agree with you in that battery life in most of the android phones is terrible)
With my Galaxy Note, the battery life improved, considerably after 5 or 6 charge cycles.
I've also used this tool a few times to figure out why my phone was running hot (even though I wasn't using it). For instance, last night, my Facebook app was in a bad state and was chewing up 20% CPU in the background. I killed it and everything was back to normal.
The tool isn't the easiest to use, but it might help.