What are the main disadvantages of Java Server Faces 2.0?

Question

Yesterday I saw a presentation on Java Server Faces 2.0 which looked truly impressive, even though I am currently a happy ASP.NET MVC / jQuery developer. What I liked most a

Answer 1

"JSF will output View-layer HTML and JavaScript that you cannot control or change without going into Controller code."

Actually JSF gives you the flexibility, you can either use standard/third-party components or create your own which you have full control over what is rendered. It is just one xhtml you need to create your custom components with JSF 2.0.