I haven’t found anything that significantly annoyed me yet.
When I’m playing music and there’s cover art, it’s now displayed on the Lock Screen, which is nice.
When the cover art is missing, the controls are now at the bottom of the screen. Each time I see them there I start to rotate my phone, thinking I’ve picked it up upside down.
I’m sure I’ll get used to the new layout. I find this problem funny, at least today.