Hi Troy,
Thanks for your response. It does change when running ab, giving a smaller total time for the page load, but I'm not sure if and how I can break ab's total request time further. Is there a way to make is show the different phases of the page loading (waiting for response, downloading etc.)?

Also, on the same machine running Firebug I get much lower "waiting for response" values for other competing sites as well as general purpose sites. Most range in the 50-150 ms range while ours is somewhere in the 500-900ms range.

My question is what parameters in nginx can affect the amount of time a request is waiting for response? How can I try and locate the bottleneck here? How can I tell if the amount of worker process I have up is sufficient?

Thanks for helping out again :)