> Apple’s operating system offers numerous advantages over other platforms when it comes to image processing, and it is also favored by many designers for the same reasons. imgix has written tools which allow us to leverage these strengths with our service, using OS X for image operations where it provides superior quality and performance.

What advantages? If you're running these as headless servers, then what advantages does OSX possibly provide over cheaper, more powerful Linux boxes using e.g. ImageMagick (ok, ok, not having massive remote code execution vulnerabilities is one of them).