Better Rear Camera
Analysts believe that the iPhone 6s will come with an improved 12MP camera. Rumors are saying the same thing. This is exciting because it means that the iPhone 6s and iPhone 6s Plus could come with a significant rear camera upgrade.
Apple's been using an 8MP sensor for years and a leap to 12MP means that the rear camera could be one of the phone's biggest selling points. 4K video and higher resolution photos would make the iPhone 6s and iPhone 6s Plus tempting propositions.