I got the 6 on launch day and loved it, but started to feel the same as you, so for Christmas my husband got me the 6 plus. I absolutely love it and could never go back to a smaller screen. I had a Note 3 last year then switched back to the 5s. As much as I loved being back on iOS, the screen size killed me!! And I thought the 6 would be big enough to use, but I was wrong. The plus is so much better, and don't regret switching at all.
I agree that the camera on the plus is better. It's not a hugely drastic difference to me, but the difference is there. Pictures of my kids playing, running around, etc, are much better on the plus.
The battery life really is awesome. I'm one of those people who charges their phones every night (being a SAHM with four young kids, I just didn't want to ever be stuck with a dead phone in an emergency), but I thought I charged my phone last night and forgot, woke up this morning with 20% and a sick kid. Was able to take my daughter to the doctor, get food, go to DMV, and get home before my phone was so low that I finally plugged it up (this includes the browsing and playing games from waiting at doctor and dmv). I never would have been able to do it with my other phones!!