It does what it is supposed to do, but also does it WHEN it is NOT supposed to. It is often triggered when my (overloaded) browser takes a bit longer to render a page, which is VERY annoying. What makes it worse, sometimes pages REALLY timeout if the server is down and this extension doesn't react to that. The additional minus point is the lack of any configuration options to, say increase the timeout or completely disable that "feature". Besides that, it would be nice to have it work from the context menu on links so the target pages could be instantly looked up on the Wayback Machine. All being said, I don't have much hope any of this will be fixed as I've seen many people have complained about the same problem and nothing has happened...