What are the under documented differences between iPhone 6s and iPhone 7? I know about Apple spec sheet comparison of the devices it currently sells (iPhone 7,6s, and SE) but I'm curious about what isn't usually on the tech spec sheet like RAM and battery mAH.
iPhone 7:


3GB of RAM (Plus only)
2nd generation Taptic Engine


iPhone 6s:


2GB of RAM
1st generation Taptic Engine