Suite runs faster with JBossTM (vs DummyTM).
A explanation for JBossTM over performing DummyTM in spite keeping a tx log on the disk (which dummyTm doesn't) is the fact that it has 2PC optimisations for situations where only one resource is registered. In other words if there is only one cache participating in the transaction (most of our tests are like that) there won't be 2RPC but only one.

It would be good to run the local test suite with JBossTM and CoordinatorEnvironmentBean.commitOnePhase=true and
CoordinatorEnvironmentBean.commitOnePhase=false on the hudson environment. This would test transactions better.