Users of the WordPress plugin "Smart Slider" praise its extensive customization options, user-friendly interface, and professional design templates. It is noted for its powerful features and stunning results, with the free version already offering substantial functionality. The plugin is appreciated for its versatility, speed, and intuitive use. Many users highlight the exceptional customer support, which is quick, professional, and helpful. However, there are criticisms regarding its performance with Elementor, responsiveness on mobile devices, and certain functionality bugs. Users also mention that full responsive design capabilities and some advanced features are only available in the Pro version, which requires an additional purchase.