Transparent Caching Solutions - Information Wanted

I guess I could claim squid's ICMP RTT measurement neighbor selection
routing thing as another big win, but I'm sure it flies in the face of
all that is Decent and True with the Purists out there.

i wouldn't argue that it's impure, but rather that it's not universally
effective since ICMP does not share all possible fates with IP. now if
squid used SONAR (which has history and trend analysis and so on) then
we'd be drunkenly singing together the praises of the resulting system.