Show me some A/B testing showing a conversion increase when Retina proofing your website.

Old people with an iPad3 won't see the difference between a non retina and a retina website. They'll see which is the fastest and the easiest to use (because usually, pixel perfect guys are not too smart about UI.)

Retina-ready is a scam. We have neither the tools (SVG support too weak, no <picture> element, no good navigator.connection...) to provide a meaningful retina experience while respecting other users.

Speed trumps "beauty". Most often.