Gatsby v2 aims to enhance the already fast performance of Gatsby v1 by reducing JavaScript load and leveraging improved libraries like React 16 and @reach/router, which collectively decrease client runtime size by 31%. The article discusses the importance of measuring site speed with tools like Lighthouse and WebPagetest, which provide metrics such as Time to Interactive (TTI) and Speed Index to ensure a site is truly fast beyond just appearances. Gatsby v2 builds on the solid foundation of its predecessor by maintaining an optimized default configuration and offering a pluggable architecture, thereby improving speed and developer experience. By following the migration guide, users can upgrade to Gatsby v2 to achieve these performance gains, ultimately delivering a faster, more interactive experience to end users.