Slow SharePoint 2013 April 2013 Cumulative Update Extraction

When running /extract against the April 2013 Cumulative Update, it takes… hours.  Using Process Monitor, it appears that the CU is going through the entire CU exe to identify and extract the files, in a one-by-one process.  For example, we’ll look at the extraction of two files, edumui-es-es.msp and edumui-et-ee.msp. First, the extraction process finds [...]