Canon 70-200/2.8 II VS. Sigma 120-300

I'm looking to grab a tele for portraits, birds, sports, and general use and am able to get either of these lenses for the same price.

Which would you recommend and why? So far I've picked up the Sigma is obviously much heavier and larger, while the Canon is optically perfect, sealed, and stabilized but only goes to 200mm.

you talking about non OS sigma? I wouldnt. The newer OS model seems much better.