I have grokked the sources for who... it seems that the version posted on
RedHat's ftp site is fixed. I would recommend updating who. It will work
properly for large utmp files, and the latency is minimal. However, with
such a large user base, I agree that 'w' should be used. Just remember to
apply all of the patches (if you d/l the SRPM) before compiling.
-Phro