The author has posted a follow up here -- http://drew.roon.io/responsive-retinas-strike-back http://drew.roon.io/responsive-retinas-strike-back -- that offers s

The author has posted a follow up here -- http://drew.roon.io/responsive-retinas-strike-back http://drew.roon.io/responsive-retinas-strike-back -- that offers some alternatives for getting around the extra download issue (which a number of people brought up, including @ricardobeat in the comments).