Reproducible 100 % of the time on a new ee stack with a wpfc.
If I install new relics php agent my ttfb results on webpagetest.org are 2-4 seconds, stop the new relic php daemon and disable the new relic monitoring in w3tc and back down to reasonable rate (.1 to .4).
Another side affect of this setup (ee, new relic, wpfc), xml sitemaps by yoast have malformed xml, reproducible 100% of the time. (turn off new relic and it works fine).
This sounds like a new relic issue and not a ee issue, but i bring it up here because ee stacks with new relic are probably the norm, no one else is experiencing this>?