Proof by reputation doesn't cut it here. He needs to demonstrate either that it is impossible to reasonably configure Squid to do very little paging or, in the alternative, that a non-paging instance of Squid performs unimpressively compared to Varnish -- at least to support his stated thesis. This is not to say either Squid or Varnish is better, only that his criticisms of Squid appear to be unfair or naive or very poorly stated on their face.