[pcwalton]

I doubt Peacekeeper is representative of real Web pages. It primarily benchmarks things that are easy to measure. Peacekeeper also has several bugs:

* It accidentally benchmarks setTimeout clamping. https://bugzilla.mozilla.org/show_bug.cgi?id=610077 is a dependency of peacekeeper. https://bugzilla.mozilla.org/show_bug.cgi?id=608648 is an example in which setTimeout clamping affects the score a lot.

* Its benchmark of array.splice() is extremely strange: https://bugzilla.mozilla.org/show_bug.cgi?id=592786

* Its layout benchmarks do not really stress layout and instead either stress basic painting operations or DOM accessors. Most pages do not sit there calling style.top in a loop over and over.

* It sets MozTransform only in Firefox without setting values in Chrome: https://bugzilla.mozilla.org/show_bug.cgi?id=920659

And so on.

There is no reason to think that Peacekeeper's JS benchmarks are particularly better than V8's; in fact, they're probably worse, due to the proliferation of microbenchmarks. You'd get about the same effect by going to jsperf.com and clicking around.