Difference between 2 methods of adding a CSS files in theme.info? What is the different between these 2 methods of loading a CSS files? 

; Method 1
css[typography.css][name] = Typography
css[typography.css][description] = Typography
css[typography.css][options][weight] = 99

; Method 2
stylesheets[all][] = css/typography.css


Method 1 means the CSS file is loaded further down the page head, which I need for my theme. However from looking at the documentation it seems Method 2 is more standard?
Method 2 is provided by core (probably why it seems more standard, it'll be used more often).

Method 1 is something specifically provided by the Omega theme.

I think the only reason to use Method 1 is if you want to be able to control the use of the stylesheet through the optional stylesheets setting in the UI.