Please don't write misleading reviews. You don't have to pay anything to find out which sites are supported or not, even if you exceed the free limit: https://www.locoloader.com/online-downloader/

As for download speed, it depends on the speed of the target website. Since all content is downloaded directly from the source, Locoloader cannot affect this speed. However, you can easily increase the download speed by enabling multithreaded/parallel downloading in the browser: https://www.makeuseof.com/enable-parallel-downloading-browsers/