I have yet to switch to using Tomcat 6. I still use 5.5.whatever. I'm wondering if there are any significant performance improvements that anyone has noticed that would make me want to switch? I'm not concerned about any new JEE5 features specifically that might be available in Tomcat 6 unless they are performance related.
I'm not using it either, but I remember an extensive I/O scalability comparison that showed impressive improvements for TC 6 due to its use of NIO. That's talked about here, but the original blog seems to have gone AWOL.