I have yet to find a good benchmark on JSF performance. I know what you are thinking, it depends on your code/design/database setup, etc. I know that you have to optimize many things before you need to optimize your presentation layer (for instance you should see how good your database schema is), but let's say for the sake of the argument that we have reached the point in which we must review our presentation layer.

JSF is session-intensive. I've read a bunch of times that this can be a drawback when it comes to writing scalable applications. Having big user sessions in a clustered enviroment can be problematic. Is there any article on this? I'd hate to go to production just to see that the great JSF lifecycle and CDI integration have a huge cost in performance.