I have compiled NSC data from immigrationwatch.com website spanning over the past 4 weeks or so. Based on that data, the average time from RFE response received status to case approval is 11 business days. This average is based on approximately 16 cases. I know some people have been waiting a lot longer though (pcOR03, bhakum and others). On the other hand, a few recent NSC-EB1-OR RFE responders in this forum have had their cases approved within 3-4 days after NSC received their response.