Quoting Perry E. Metzger (perry@piermont.com):
> "Michael D. Spence" <spence@panix.com> writes:
> > > "Larson, Timothy E." <Larson.Timothy1@mayo.edu> writes:
> > > > Do most people leave the installed components here and update your
> > > > path and manpath?  Do you use pkg_add's -p option to specify the
> > >
> > > Don't even think about moving them. Things will fail horribly at times
> > > if you do that.
> > 
> > Some systems and packages seem to use /usr/local (for example, ISTR that
> > some man pages refer to it).
> 
> Nothing in NetBSD uses /usr/local as built.

When I first used BSDi, it came with many tools that were not part
of the Unix OS per se, but were important: elm, gated, many many
others.  You don't want third party tools in /usr/bin/ (hello, most
linux distros).  You don't really want them in /usr/local/bin/
either.  BSDi used /usr/contrib/ for that stuff.  If updates are
available, they get put THERE.

Similiarly, I put my scripts and programs into /usr/local/.  I
*really* don't want the ports/packages mixed in.  When I update the
OS, I really like to update the packages to that version too.
Separation makes it easier to do.  /usr/local/bin/ is in my path
before /usr/pkg/bin/ so I can override the occasional program, but
the segregation makes maintanance easier.  And maintanance is by
far the greatest cost of running computer systems.