So I'm just going to put this out there, and then we can all handle the emotional consequences together: if you are thinking of buying a new phone, and you have anything older than an iPhone 6, you should buy an iPhone 6S Plus. It is the best iPhone ever made, and it is right now the best phone on the market. If you're upgrading from an iPhone 5S or anything older, it will blow your mind.
Note that I said the 6S Plus, not the 6S. I am convinced that in another year or so every phone will be the size of the 6S Plus, so if you're going to jump in, just go all the way. You'll get a slightly better camera and a little more battery life out of the deal as well. The future is here. You should face it with a gigantic screen.