Hahaha! I knew Angie would say that!!!
I like the size of 6. Why? Because I like my phone to be small enough to fit anywhere. And also because I have an iPad mini, so if I need to see something on a slightly larger screen, I use the iPad.
That said, I'm eagerly waiting for iPhone 7. I don't know what it will look like; I just know that I WILL buy it!!! I usually update my iPhone every year but didn't get the 6S (I still use iPhone 6).
However, my husband just got the iPhone 5SE - the limited edition phone that's the size of iPhone 5 but has all features of iPhone 6S - and you CANNOT compare the picture clarity at all. His phone's camera takes crystal clear photos in pitch dark!!! And it's faster than my iPhone 6 too.
With iPhones, I'm of the opinion that the LATEST is always best. If you have an iPad or tablet of any sort, get the 6S. If you browse the Internet a lot on your phone and don't have a tablet, the 6S plus is worth it.