Hi Lio,
The benchmarks were derived from Remoting release 2.0.0.GA. The versions of Remoting in the various releases of AS 5 come from a different branch, beginning with release 2.4.0. Before I released 2.4.0 I did a lot of testing and tuning and the performance of 2.4.0 was very close to that of 2.0.0.
The code is in SVN. See
http://anonsvn.jboss.org/repos/jbossremoting/remoting2/branches/2.x/src/tests/org/jboss/test/remoting/performance/**
The performance test suite can be executed with the "tests.performance" target in
http://anonsvn.jboss.org/repos/jbossremoting/remoting2/branches/2.x/build.xml.
-Ron