An experiment making these more realistic measurements should use -something like Selenium/Firefox to control an actual browser to make +something like Selenium to control an actual Tor Browser to make requests.
FYI, I have written code that downloads the present Tor Browser alpha and Python Selenium client and monkey-patches them to play nice together; see https://github.com/zackw/tailwagger . It's very specialized for my requirements right now, but might still be of use to you. Look especially at what is done to TBB and python-selenium by the patches under pkg/tor-browser-3.0a3 and pkg/python-selenium-2.33.0, and the TbbDriver class in client/tbbselenium.py .