Noticed two things so far that haven't been mentioned:
When you scroll up in messages to read old messages, the keyboard hides so that you can view them on the whole screen. Super useful!
In Settings > General > Accessibility > Physical & Motor there seems to be a new Assistive Touch Menu that looks like it could be very interesting for gestures in the future for iPhone...
Finally!! I've been waiting for that. So sick of going to another message and then back to the original so I could see more screen. Very happy to hear this.