How different is L2 2008 from L2 2009?

Hi - I have the books for L2 2008 (Schweser). Is L2 2009 much different? I remember that it was ~40% different from 2007 to 2008 - is there a similar difference this time? Any thoughts on this would be appreciated as I am trying to decide whether I need to purchase 2009 Schweser books. Thanks!