install 2005 or 2006

I had to reformat today and can either install latest updateof solidworks 2005 or 2006. i have been using 2005 for a while nowbut have no experience with 2006. can anyone offer any insight.stability, performance.....

i have a amd64 4000+ with a quadro 4000fx.

thank you

brianSolidworksGeneral