Efficient in finding the dead links, but while doing so, it produces extreme traffic that sends my ISP into red alert and into bugging me with recaptcha checks. Meanwhile, Firefox comes to a halt and crashes from overload. The hit list is not saveable, so there is no other way about it than starting all over again, and going into an into an endless feedback loop. Sadly, I have to uninstall it, though I have no functional replacement for it.