The document compares different transport mechanisms for sending data between a client and server in a GWT application. It discusses RequestBuilder, JSON parsing with JSONValue, Jackson for JSON serialization/deserialization, GWT-RPC, REST with JAX-RS and resty-gwt, Protocol Buffers, state synchronization with shared objects in Vaadin, and event-driven communication using CDI events in Errai. Each method is evaluated based on advantages like being standard, readable or optimized formats, and disadvantages like boilerplate code or tight coupling to frameworks. The document considers usage statistics and seeks audience questions and feedback.