Re: cache effectiveness testing

Since we're just trying to isolate the impact of caching & nothing
else, it may be advisable to perform an initial run through the sites
in a Private Browsing session, to prime the network connection. This
would remove variability related to caching DNS requests & other
network issues. That can easily add a few hundred milliseconds of
delay to whichever software package you test first (in this case
Firefox run 1).