This argument is compelling.  Arthur, can we strike the words "after sorting it" and "leaving it sorted" from the "Finding the median" section of SRFI 132, or do you think that's too big a change?  It's basically saying that we no longer guarantee a specific side effect of the vector-find-median! function.  Here's a proposed paragraph for the Status section:

<p><b>Post-finalization note 1</b>:  It is recommended that implementers use an O(<i>n</i>) rather than an O(<i>n</i> log <i>n</i>) implementation of <code>vector-find-median!</code>.  This improves performance, but removes the guarantee that the vector passed to this procedure is returned in a sorted state.  Instead, it is returned with the elements in arbitrary order.</p>