When I first got my Note 3, it really did cut into my iPad usage. I found that for average web consumption....reading websites, news articles, watching youtube and wasting time on FB/social networks, it was more than sufficient even at the size differential (Note 3 has a 5.7" screen).
For composing emails it was OK in lanscape mode, although the pop up keyboard still obscured more than half the screen so it really didn't give you all that much of an advantage. Might be easier to type using both thumbs but I prefer seeing the full text box that I'm typing in on message boards, etc. So the "benefit while in landscape" was totally wasted IMO. Perhaps iOS8 does a better job of this but...doubtful to me.
Ultimately, for any real work I'd still prefer my MBA, although the iPad is fine for emails and light word processing, followed by a very distant last place/no other alternative available in the Note 3. I'm almost positive the 6+ would fall in the same place for me here also.
Wishful thinking for anyone other than a very lightweight text-oriented user in other words. Tablets still have their place.