One thing that is wonderfully improved are the controls for entering text in a message. Full featured font size and colors (use advanced editor control). It also is smart enough to recover text if there's been a glitch in posting.
I'm getting used to it and much, much appreciate the new look. it's fresh and inviting. I just hope that they overhaul the Mac OS and the iOS so that they look clean, modern, & colorful, instead of 19th century industrial grey with, in the case of the iPad and iPhone, mechanicial date pickers!
I also dislike the email notification default being set to 'on' when replying to a posting. EDIT: To add to this comment, I keep turning the setting off and it won't remember it.
Click here: https://discussions.apple.com/index.jspa
Then click: Your Stuff
Then click: Preferences
Select the: Email Notification Preferences
Select Yes or No as needed then click Save.