My wife and I had the iPhone 6. She upgraded a couple weeks ago to a 6S Plus, as she emails a lot for work and the longer battery usage worked better for her. I never thought I would ever go with a plus, as I thought the 6 was the perfect size after the 5S.
After holding hers and messing around with it here and there I just swung by AT&T the other day after work and took a chance and upgraded to the 6S Plus as well. It was a scary move, but I'm very happy with it! Love the battery life and the larger screen. Still getting used to pocketing it with my work uniform, but it'll pass. I got the Apple Leather case as it doesn't add any bulk and gives it some protection and grip.