Some quick things I've noticed:
1. Weather doesn't crash when you delete a location from the "world" view
2. Weather: Fonts are thicker
3. Settings: Fonts are thicker
4. Control Center: Music scrubber bar is thicker
5. Calendar: Mini dots in month view for events on each day!!!
6. Camera: Much more stable, seems quicker, though not quantifiably verified yet.
7. Messages: Thicker font (seems like the font style "normal" has replaced "light" in many places throughout the system...)
8: Messages: Previously, names on the top of a message thread were pushed off center to fit the words "Messages" and "Contact". Now the name and surrounding words truncate to keep the contact name centered no matter what. "Messa... Person's nam... Contact"
9: Lock: Time keeps correct Y-axis position when waking up phone instead of shifting to the middle arbitrarily (and thicker font for "slide to unlock")
10: No evidence of overlapping objects in titles (or % charged)
11: Unlock icon animation seems 20% quicker or so.