Angular 2 offers significant improvements over Angular 1 including better performance, more powerful templates, dependency injection with lazy loading, and support for server-side rendering and web workers. The document outlines the key differences in directives, data binding, dependency injection and other areas between Angular 1 and 2. It recommends upgrading to Angular 2 due to the benefits, though notes it requires rewriting Angular 1 apps to use Angular 2's component-based structure.