Minor Description
As far as I have experienced the return types of getResultList() seem to be Serializable, therefore I would expect the same for org.apache.openjpa.kernel.DistinctResultList.
This does not seem to be the case, since I broke my remotely exposed DAO method by adding the DISTINCT keyword to the query it executes.
I can easily work around this by returning a new list based on the DistinctResultList, but to me this occurs as a minor inconsistency.