The functionality within Outlook is the same and there is also no (noticeable) performance increase by using the 64-bit edition.
Another reason could be that you have used special characters in the folder/file names that you have added to your Favorites section, Calendar/Tasks/Contacts groups or the Shortcuts Navigation.
Some (rare) characters seem not to translate well to the Navigation Pane xml-file and will cause the writing or loading of it to abort.
Aside from the preparation steps, this guide informs you about what to expect when you start Outlook 2013 for the first time after you upgraded and how to troubleshoot several issues you may encounter during or after the installation.
Furthermore, for those of you who need some transition time, you’ll find a Ribbon-Customization-file in this guide to make the Outlook interface look similar to the one found in Outlook 2007.
[more] So in short, "Favorites" and "Favorite Folders" DO NOT mean the same thing.
This guide contains a lot of preparation and other information to get yourself ready before you double click on that file.What you’re going to do here is install Chrome, export your IE bookmarks into a file, import that Bookmark file into Chrome, and then redo the steps above to import your bookmarks from Chrome instead of Internet Explorer. Now, all you have to do is go back to the top of this article, and try to import your bookmarks again… Microsoft is conducting an online survey to understand your opinion of the Technet Web site.I switched back to [Folder List] view and navigated to [Public Folders Favorites] and there it was.I right clicked on the "Favorite" that I had just created and selected the "Add to Favorite Folders" view, then it was added to the "Favorite Folders" window in the [MAIL] view.If you used Internet Explorer in Windows 7 or 8, all your bookmarks were saved in your Favorites folder.