CC and Lester are a wash. ERA+ are the exact same over the past 3 years.
To be honest, if we're looking at 2012, I'd much rather have Lester. He's younger and has fewer innings logged on his arm in the past 3 years. He's good for 200+ IP a year at an ERA of around 3.30. He's younger than CC, too.
Talent is a wash, as indicated by ERA+, ERA, FIP, etc. Going forward, I'll take the guy with the lower innings over the past few years.