To what degree have any of us done massive RDA work in our catalogs, and similarly, to what degree have some of the community's MARC programming libraries have been modified to account for RDA rules?
For example, has anybody done any large scale find & replace operations against their catalogs to create RDA fields with values found in other MARC fields? Why or why not? Similarly, RDA seems to define a publication field in MARC 264. Correct? Yet the venerable Perl-based MARC::Record module (still) pulls publication dates from MARC 260.  A colleague found a bit of a discussion of this issue from the VuFind community.  Which leaves me to ask another question, “Why is there so much business logic embedded into the MARC cataloging rules?”
Alas. How in the world is the library community ever going to have more consistently encoded data so it can actually disseminate information?
 MARC::Record - http://bit.ly/2px2sC6
 discussion - https://vufind.org/jira/browse/VUFIND-749