MetaFrame has several key advantages over a vanilla TSE installation such as:
1. System management tools to allow manageability and scalability on an enterprise level.
2. Application publishing that allows mission critical applications to be deployed with greater ease.
3. The ability to shadow a user's session remotely aids support and training personnel.
RDP is included with TSE, as are the Session and User objects although both are supported by MetaFrame.

Reference: MetaFrame Administration Module 3