If you're referring to intra-JVM Remote EJB invocations, then yes. In general there is less overhead to an intra-JVM Remote EJB invocation since the network stack interaction can be skipped. As far as pass-by-copy semantics, by default the EJB spec requires that behavior
even for collocated calls in order to preserve location transparency.
We do have a vendor-specific option to use pass-by-reference semantics (see sun-ejb-jar.dtd in $APS_HOME/lib/dtds). However, that only applies to the case that the caller and callee are in the same application.
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