A few thoughts after using s7e for a while:
1. Handling - somehow the larger size makes it harder to grip when taking in and out of pocket. I'm not used to large phone, my ex s6e always feel like it's secure in my palm. Also s6e flat back gave the feel of being extremely thin. Start to miss the 5 incher already lol. But of course there's the battery trade off for thin profile...
2. DAC - s7e is noticeably more gentle on the highs and transient, but not as clear as s6e, but richer sounding. Some will think s7e sound muddy and s6e sound harsh. I won't say which one is better just depends on what you like. Personally I kinda miss the clarity of s6e lol.
3. Main camera - it takes much better shots in low light, but at the same time with a lot more over sharpening artifacts, to the point sometimes it looked harsh on certain object with rich texture. S6e has more organic look, but also means less apparent sharpness (but more details due to higher resolution). S6e also take slightly wider view but vertically it's very narrow. S7e is much more suited to general shooting and easy to stuff more things inside frame, very often I need to step back quite a bit to fit more people or object in frame simply because I can't get the full body to fit in the frame. And doing that, you'll leave more empty space on both sides, makes it awkward to frame. (As for aspect ratio, IMHO 3:2 ratio is best for landscape and 4:3 is best for vertical)
The rest pretty much covered in most public reviews.