Users appreciate the Otter Blocks plugin for its ease of use, extensive functionalities, and ability to create professional-looking sites without the need for additional theme builder plugins. It is beneficial for both beginners and experienced developers, offering useful blocks like the Advanced Heading block, adding customization options, and integrating AI features. The plugin helps users save time and money by providing an all-in-one solution for site building, and its customer support is highly praised. However, some drawbacks include slow loading times, font/icon optimization issues, annoying pop-ups, and occasional bugs. It works well overall, but some advanced features may require payment.