Users appreciate the Autoptimize plugin for its effectiveness in significantly improving website speed and performance. They highlight its ease of use, extensive features such as image optimization, lazy loading, CSS/JS minification, and critical CSS. The support provided by the plugin’s developer, Frank, is consistently praised for being prompt, helpful, and going above and beyond expectations. However, some users experienced issues such as site crashes, increased server load, or page slowing instead of speeding up. There are also occasional compatibility issues with other plugins. Overall, while the plugin has its drawbacks, its performance optimization features and responsive support make it highly recommended by users.