Michael,

At Penn State, at least for our maps records (haven't a clue about other format teams in my department) we always upgrade an AACR2 (or earlier standard) record to RDA standard, largely because we are PCC members in NACO and BIBCO programs that require that level of work. There's always a mixture of record quality on OCLC though, so in many cases accepting a high-quality or even better-quality AACR2 record without enhancement should be fine for institutions should they choose that path. I'll be interested to see what other responses to your question are, but in my opinion it is the quality of the record itself (accuracy, completeness, use of authorized access point headings) that is of more importance than choice between AACR2 and RDA. 

Paige

---