If you're using AdBlock Plus, every single page load will block until AdBlock Plus has finished running expensive regexps against the DOM. (That said, the browser really is bloated and slow, but invasive extensions like ad blockers will slow down the entire experience.) Just disabling AdBlock Plus won't necessarily speed up the browser though, because ad bloatware may slow down the browser even more than AdBlock Plus. Instead, try uBlock Origin -- it is much, much faster than AdBlock Plus, and supports all the AdBlock Plus blacklists. Your web experience will fly again.