I got both 6s and 6s+. Use the plus at home. If I had to choose it would be the 6s. I prefer the more pocketable phone. Much easier to fit in to every day life.
In terms of usage, 6s+ beats 6s any day. The only disadvantage is of carrying it around especially wearing skinny outfitsit's a matter of personal tastes ....
I'm not ok with carry an iPhone 6S+ during summer, with only jeans or trousers and a shirt on.
During winter it doesn't matter, because i have plenty of pockets available anyway.
but having to choose one, I bought an iPhone 6s
I want the 7S plus
6s. I have my iPad Mini if I want to watch videos on a bigger screen. Plus, I like the fact that my 6s fits comfortably in my jean and pant pockets when I'm out or at work.