Do you use S-pen? If not, you have lots of other options to choose from besides Note 4.
I used Note 1 and now using Note 3 for more than a year now. I don't know about you - but I am stuck (in a good way) with S-pen - for my personal use, work etc. So if you use a lot of S-pen, there isn't any relevant alternative for you.
Respectfully, Note 3's S-pen was a big jump, even for you using Note 2, not to mention the 3Gb ram, full HD screen, etc.. And Note 4? Wow... i wish I could change but wifey says wait for Note 5...
Battery usage/life? I was given an extra free battery on the day i bought my Note 3. I alternate between the 2 batteries. I don't really worry about battery dead - each day when I leave my home for work/shopping/church/tennis/ - I have my Note 3 (with whatever existing battery left) and a fresh fully charged battery. No need to carry bulky battery booster/charger or worse, searching frantically for a power socket. My wife also carries the Note 3, and she does the same too. Lately, my youngest girl switched form IP4S to Galaxy S5 - I bought her an extra battery to follow the same approach - always carry a fully charged battery when she leaves the house. She has since freed from bulky charger or power socket. And remember, you have 3200 battery in Note 3, more in Note 4..
Recently, I got to try my SIL's iPhone 6 plus. The brief experience reminded me of why I switched to Android more than 3 years ago - SD card, simple file transfer, can change battery, no need iTunes to upload songs/pics, multi-tasking, installed 3rd party apps to watch tons of streaming TV dramas, movies...
Android is the way to go, but this is just my perspective.
Good luck,
Bob