Great news! You'll be happy to know that this is just the beginning. The Seam QA team is working on several performance enhancements that are going to give Seam some nitro!
Actually I monitor the seam-dev-mailinglist closely ... so I know about all the
efforts and findings you've (Jay Balunas in particular) made but not yet released.
We are eagerly waiting.
You probably saw on seam-dev, but if not you should upgrade to JSF 1.2_10 asap. That contained a big fix for performance that we found when JSF applications are under load.
Thanks for the suggestion on the JSF. We updated to it but this time it didn't buy us anything noticeable in terms of performance. Every application is different from the other I guess.