[munificent]

Off the top of my head:

- Resizing windows from any edge

- Flipping the scrollbar direction

- Automatically hiding scrollbars

- Traffic light colored buttons on windows

- Whatever the three window buttons are now

- The dock

- "Close without saving" becoming "Delete" in some apps

- Floating alerts versus slide-down anchored alerts

These are all fairly minor, but there's a lot like this and it all adds up to things not quite working the way you expect over time.