It can work pretty well at times, but it's far from perfect. Many a website will look quit poor, partly due to a lack of settings to tweak the exact colour alterations and partly because it misses certain page elements occasionally. I understand imperfections are to be expected, but since I would rather avoid ugly websites, it prevents me from using it on most websites I would wish to. I instead end up relying on custom CSS stylesheets, which this is meant to replace.