Office 2013 - What is the difference?

Yesterday Microsoft rolled out their latest version of Office.  Office 2013.  - I have been using this for a while now and put simply, I still see this as the most complete productivity suite available on any platform by a very long margin.

But it is not free - far from it.  Microsoft is trying to convince the average user to subscribe to their suite of tools for $100 USD per year that allows you to install it on 5 devices.  Not to bad, but not Google docs free.

Is it worth the upgrade from the already very capable office 2010?  Make your own mind up, take a look at CNET's review below.