There are definitely differences, some big and some small. The main thing is that involves the major test change last year that resulted in the addition of Integrated Reasoning. For this reason alone, it is a good idea to upgrade to the new version.
All of the tests now come with the New Kaplan
GMAT Premier 2014 book. Here is the link to that:http://www.amazon.com/Kaplan-GMAT-Premi ... 161865053X
Let us know if you have more questions.