Nick Heer writes:

Interestingly, because of the way AdBlock is built and the number of iframes that are on popular websites, AdBlock often slows down browsers, though Filloux found otherwise. Apple’s new integrated content blocker doesn’t have this issue. But that’s something of an aside.

I have installed AdBlock in Safari on my MacBook Pro and in TenFourFox on all my G4 PowerBooks and on my G4 Cube. In Safari I use AdBlock only on specific, abnormally ad-heavy websites, and AdBlock speeds up webpage loading and website navigation noticeably; Safari doesn’t lose any responsiveness and doesn’t seem to be using more memory or CPU resources than it normally uses. On my vintage PowerPC G4 systems, AdBlock is permanently on, and I’d say it’s a must if one wants to browse today’s Web at decent speeds. Sometimes it makes the browser consume a bit more CPU, but it’s worth the tradeoff, since loading any ad-serving website without AdBlock would eat up the same additional CPU cycles anyway. At least with AdBlock I can browse much faster on a Mac with a PowerPC G4 (or even G3) processor.

(And speaking of browser speed, I don’t know what’s happening to Google Chrome lately, but on my MacBook Pro it has become so sluggish that’s hardly usable with more than three tabs open.)