This video was recorded on iPhone4S at 1080p 30FPS.
Looks pretty damned good.
I'll be happy to have 4K recording on my iPhone 6S+

NEW FEATURES:

#1 SPLIT SCREEN viewing (with 2GB of RAM models of iPad and iPhone)

#2 New voices for Siri

#3 LOW POWER MODE (disables features that use energy under 20% charge)

#4 Picture-In-Picture (iPad)

#5 Public Transit Directions

#6 Selfie hiding folder

#7 Notes App

[You can take photos from within the Notes app and add text, you can draw and sketch in the Notes app, and you can even quickly and easily turn any list into a checklist. So long, wish list and to-do apps!

Also great is the Notes app’s new share sheet, which lets you embed websites, photos, maps and more in a Note without ever leaving the app you’re in.]