What's Content Taxonomy's performance overhead?

We're thinking of using Content Taxonomy for the articles on our site so we can get tokens for the terms we assign for them which we can get into the URL for pathauto. With 4000 articles, 20000 daily visitors and most importantly not enough money for servers (which are already a bit slow), performance is a concern. How much would using Content Taxonomy slow things down? Is there a speedier way to make terms available to pathauto?

Many thanks for any help we can get...