Its been such a long time since I've used Squid that I didn't even know that there was a version 3 out!
I decided to try squid3 and then found that I was unable to use icp for some reason with squid 2.6.
I only consider squid as a forward proxy, varnish does a better job as an http accelerator, in my opinion.
But why does squid take so long to restart? Who knows? I've been using reload instead and that is much faster.
Squid's support for routing domains directly and through other proxy servers is awesome.