I guess I don't understand what you mean by "productivity"..what does Android offer for productivity that iphone does not?
Both have office apps...google docs...great email..multiple ways to text/sms/chat/etc.
If by productivity you mean split the screen up, I guess I don't agree that's being really productive.
The note taking feature for Note 7 is the biggest advantage. I take a LOT of notes and so, having this available, and connecting to OneNote will be great (or Evernote for that matter).
You just contradicted yourself and you didn't even know it!

You can use your split screen for notetaking!
I use the split screen A LOT for watching YouTube while taking notes at the same time (I learn how to do different things for myself in order to save money; YouTube is the best! lol). Or using another app while taking notes. I could not do this on my iPhone. I better have a pen and a pad handy.