I have recently bought a refurbished 15" Retina MacBook Pro. The display is stunning and it is a pleasure to edit and view photos on it.
I took the opportunity to redesign my Web site to display images at the most favorable resolution using picturefill and make it more responsive so that it displays at an appropriate size on phones and tablets.
I did not update older photos but starting from now, I'll provide responsive images. Using multiple export settings in Lightroom and a TextMate snippet to generate the corresponding HTML code does not weighten my workflow too much.