This. If anything, OP, I made this upgrade, from a 6s, but to a 7 Plus instead.
I did my homework very carefully and found there actually wasn't enough at all to warrant moving to just the standard 7. A lot of the 7's new features (e.g. Wide Colour and Water Resistance), you actually really forget about them after a while, seriously you do. And having the same design doesn't help this either.
In contrast, I found one of the best features of the 7(Plus) is actually the stereo speakers - they're a HUGE upgrade over the cheap last-minute ones found in the 6s. If you listen to a lot of music/videos out loud, thats good.
However, the 7 Plus not only has its exclusive dual cameras (adding future proofing in that department), but I it also has the benefits of the Plus phone, that being, larger screen and vastly better battery life. To me, those two felt more important than the 7's other new features. As for the negative of larger size, I actually forgot it was bigger in a week or so. That would be a very justified upgrade.
Jet Black is really nice, its very reminiscent of the old 3GS Black iPhone if thats your thing.

Just keep in mind its also exclusive to the higher storage tiers.
But really, please do have a look at the Plus. People aren't calling the 7 a "6s painted in black" for nothing.