Thats my thoughts too......what takes advantage of the extra size for the N6?
The N4 adds a few extra features and not just extra size......
True the Note 4 has its specific phablet features which are very nice. Nevertheless though I find just extra screen real estate in itself very nice to have for many general tasks. Reading, editing text, watching videos, gaming, using the calendar, maps etc, for all of those I like to have as big a phone screen as possible. I also like it for apps like Spotify where the extra space gives a better overview.