Just for fun, I decided to measure our site performance in three ways:

1. Apache server
2. Apache server + Varnish
3. Apache server + Varnish + CloudFlare

I measured this by accessing the normal public site (through CloudFlare) then setting up alternative URLs to the same website. I know there could be lots of metrics to use for this, but I focused on just the "time to first byte" type measurement. I measured this every minute using Rigor (http://www.rigor.com), which is a great tool for this purpose and other purposes. After a couple of weeks of measuring this, here are the most recent results. The chart is hard to read, so here are the details.

1. Apache

2. Apache server + Varnish

3. Apache server + Varnish + CloudFlare

Analysis

As you can see, the Varnish solution is he fastest. Interestingly, the CloudFlare solution is the slowest. I don't know if that's because of how it interacts with Varnish, but I suspect it's another reason. I am guessing it's because the CloudFlare service is another webserver (nginx, I think) and it's doing a bunch of things to the web content "on the way out".