Tomcat/Cocoon Performance on Production Sites?

Saqib Ali asks: "A Tomcat/Cocoon setup can be used as a framework for publishing XML content. I have this setup running in testing environment for about 5 months now, and would like to move it into production. Is anyone using a similar setup and can comment on Tomcat's ability in handling the load from a production environment, or should we look at other Java Servlet engines like BEA, Jetty or Resin? If Open Source solutions can't work under these kind of pressure what should we be looking at in terms of different commercial solutions for publishing XML content?" A similar question with respect to Tomcat and Jetty was discussed in this previous discussion. What effects does using Cocoon have on Tomcat-based environments?