First of all, this is the most thorough WBGP yet.
somehow it seems that firefox is focussing more on benchmarks rather than actual real world usage.
I don't think so - proper page loads and battery life are important considerations.
I agree that Mozilla did not do a right thing in copying Chrome's release cycle, but at least they're trying - for example, they're trying hard in bringing down memory usage by increasing the garbage collection frequency(check this out in the Aurora and Nightly builds).
WBGP is basically a test of speed, and Chrome may have won in that, but Firefox is not far behind. I can wait for two or three seconds for my page to load. You can easily bring down the page load times by using addons like AdBlock Plus.
Even with the faster release cycle, this article clearly states that Firefox is still the most stable browser. Many people say that they've had numerous crashes, but its something wrong with their drivers or OS - I have not had a single crash since FF 4.0 beta 5 (or 7?), when they introduced hardware acceleration for the first time.
Firefox remains the most customizable browser, while Opera has the most number of features out-of-the-box.
So overall, according to me Firefox>=Opera>Chrome>IE 9> Safari.