I've been on Office 2013 for around 6 months. We use Google Apps for mail and it's been frustrating having my mail and calenders not sync with Outlook properly.
I know I can use IMAP ( infact thats what I was using ) and a few other bolts on ( which I purchased ) to restore functionality but it just wasn't 100%.
In the mean time I had reverted to using the browser 99% of the time for email and calendar which I have grown fond of.
Now that Google Apps sync works properly I'll give Outlook 2013 a good try.