A much better article by Digital Foundry, the wizards at Eurogamer:
http://www.eurogamer.net/articles/digitalfoundry-gran-turismo-5-tech-analysis
"That said, achieving 4x MSAA with frame-rates and details as high as this is indeed a technical achievement unmatched by any of Polyphony's competitors (Forza 3 is 720p with 2x MSAA, for example), and there is a definite feeling that Kazunori Yamauchi's team likes to push boundaries like this."