I don't like where they put the new message button (it's weirdly floating over the list of folders now, but what's the relation with that list?). There's also a

I don't like where they put the new message button (it's weirdly floating over the list of folders now, but what's the relation with that list?). There's also a mostly empty bar _above_ the menu bar (I'm old-school, I like menu bars). It wastes space, looks silly, and cannot be turned off as far as I can tell... I used to have an extension installed ("Mailbox Alert") that provides different notification sounds depending on the account receiving an email, but unfortunately that is now broken. That's a significant step back.