IMO it still has issues. Specifically Mail. If you receive an email, and read it, the mail indicator still shows it as unread. If you right click, the option is to change to unread, even though it's shown that way. If you click on a different option, say go to Sent Mail, or something else, and then back to the inbox, it takes the indicator off as being read.
Not sure what has happened to the Apple QA dept. but I feel they're not what they used to be. The release notes state a number of fixes to Mail, but they're still present. Also, the sync to Exchange is still slow, buggy, and malfunctioning. I've done a mailbox rebuild, taken offline/online, removed/readded the account. Same results.