It would give us better performance. Even if https://jira.jboss.org/jira/browse/JBESB-2037 make caching central in ESB integration javaassist would give us better performance when wise would be used standalone. Moreover it would help a lot with class loading.
When it issues would be closed may be better to choice this implementation and declare deprecated the reflection based implementation and implements any new feature on the javaassist impl.

This issue have to be detailed with subtasks