Before you give a score to every browser, why don't you back it up with something objective?
That's especially true for content-alteration extensions like ad-blockers as it's very easy to implement them in ways which work well enough with few rules but degrade superlinearly at scale. That's a big part of the issues Firefox has/had (not to mention the "depth" available to XUL extensions), but it's not like other browsers are immune.
Of course, between "should" and the reality, there's room for tolerance.
Much happier now on Safari and uBlock.
These days Safari actually shows that rainbow spinner when the background process that runs the tab is hanging, even though Safari.app itself is perfectly responsive. This usually is indicative of a problem with a site loaded in one of the tabs in the window (I believe Safari does process separation per-window), as opposed to a problem with Safari or WebKit itself.