This was the first time I attempted to upgrade to this version, before only installed it fresh. And as Microsoft correctly pointed out in their KB article you cannot upgrade to that version, it installed alongside Office 2010.
That presented a huge inconvenience. When launching Outlook 2013 it did detect and import the email accounts. However, it did not import any custom settings. Had to re-create all the rules and color categories. The worst thing was that it didn’t import the data. The biggest reason to get Office 2013 was because it handles large IMAP mailboxes better. But as it didn’t import existing data it went out and started re-downloading EVERYTHING. Because that client has rather slow internet connection I had to take that PC home overnight to let it download everything on a faster internet connection.
Good news is it does seem to handle IMAP better. While Outlook 2010 takes bloody ages to synch the mailbox and while it is thinking the program continuously freezes version 2013 pushes the process to background and it does take a lot less time. Does not synch sent items by default, rather stupid, have to manually enable it.