Use Domain In Hostname Or Not?

[Steve Simmons]

Over the years I've noticed that most folks set the hostname to the
fully qualified domain name.  We've always made them simple hostnames,
then relied on proper sendmail.cfs, etc, to add our domain as
appropriate.  Recently we've bumped into some vendor software bugs for
which the workaround is to make hostname == FQDN.  The vendor agrees
their performance isn't correct, but we're not likely to see a real fix
in the next couple of days.  We're loathe to do things different on
'just one machine', and would prefer consistancy.  I'm interested in
any and all comments on why or why not to set hostname to FQDN.