Got my 128GB 6S Plus a week ago, it replaced a 64GB iPhone 6 Plus. 2 gigantic improvements are: 1. Battery life is dramatically better! My 6 Plus would average 5-6 hours of screen on time. This 6S Plus is averaging 8-10 hours of screen on time at the same level of brightness. Considering the battery is actually smaller that's amazing. 2. Overall phone speed is astonishing! The week before I got my 6S Plus I was using my 6 Plus on iOS 9. It was very sluggish to put it mildly. Running this same OS my 6S Plus never skips a beat! I turn off none of the eye candy, on the 6 Plus I had to in order to make it tolerable. The 6S Plus simply flies! I'm 1000% satisfied with this upgrade!