When browsing a site full of JS-heavy ads, sure.

When running a browser performance benchmark, generally not - the ad block extension adds an overhead to the page. I saw this when experimenting with Orion Browser on Mac, which uses the Webkit engine, but adds support for many Firefox and Chrome web extension APIs.

In experimenting with that, I noticed that enabling extensions and using many extensions during benchmarks could easily impact on scores. Even just an ad blocker like uBO had a measurable impact on a benchmark, from my recollection.

Orion is using a web engine that was never really designed to support what they are trying to make it do. Obviously it's just code in the end but a lot of the changes will be made for convenience rather than in ways that make sense if you look at WebKit holistically, because the team is just too small to actually do that. So it is natural that performance suffers.

Depends on what sites you visit, but hooking every single HTTP call and HTML DOM isn't cheap. I often find websites with ads to be just as fast as websites without them, just more cluttered, unusable, and more of a privacy nightmare. The uBO overhead does seem to impact CPU usage, though.

I'll gladly pay the 15 minutes of battery power spent on filtering out that trash.