Official SAT Subject Guide 2006 version vs newest?

<p>So I've got the 2006 version and I was wondering if it was worth it to run out and get the newest version? I think the 2006 was the one right before the newest. Were there any changes?</p>

<p>If it's of any significance, I'm taking the Chem and the USH.</p>

<p>(Whelp good luck to you all in these last two/first two weeks of studying!)</p>

<p>Bump, anyone??</p>