The reason is simple. You wrote Blu-ray. Look at the Avatar BR fiasco and in the Cnet Samsung forum about Blu-ray playback issues.
If Blu-ray matters, you get the Sony.
I'm torn between two laptops, a samsung r580 http://bit.ly/aUXsJV and a sony vaio e series that i customized, core i5 520m, ati radeon 5470, 320gb hdd, with blu ray, the vaio is $90 more, I love the way the Vaio looks, while samsung is very bland to me in terms of looks, i'm soo torn though which one is best?