Decision: 2006 Cayenne Turbo S or 2008 Cayenne Turbo

Looking at a 2006 Cayenne Turbo S with 64,000 miles on it and Certified from Porsche to 100K miles but worried about the miles. Also found a 2008 Cayenne Turbo with 50,000 miles for $13, 000 more also certified by Porsche to 100K miles. Wondering if its worth the extra to move up to the 2008 with less miles but its not an "S" model. Would love input to help make my decision!