It seems to me that it is infinitely better to define media queries in the HTML file within the link> tag rather than by using @media only... in external CSS files.
You can have a large number of specific files modularized quite nicely and extremely specifically depending on what device is being targeted, and only the files you need will be retrieved. I can't think of a single reason not to use this method, or a single instance where it would not be superior.
And yet, I've been unable to verify this. Can anyone offer any scientific evidence / proof to support or invalidate my theory?
Thanks