No issues with my 6s+
It's a welcomed update from my 6+. Faster, snappier, really noticing the 2GB of RAM. Pictures look great, videos as well. I can really zoom in quite far and still have pretty good quality. Sometimes forget about 3D Touch but do use it time and again.
Not so sure about Live Photos though, they're choppy and not fluid as they were shown by Apple. Besides when I take a picture it's usually really quick so the beginning and end of the live picture is blurred & locking it to put back into my pocket. Thinking about disabling to save space. If I want a short video, I'll just take a video.