difference between cvsup and portsnap

[Barry McCormick]

Here at my work we use FreeBSD in production.  We have the following
debate and wish to know better the differences between cvsup(csup) and
portsnap.  One of my co-workers think that portsnap should NOT be used
and only gets the latest and greatest port collection, no matter what
version  of FreeBSD is on the server.   For example, if you are still
running a 5.4 stable box in production and use any of the portsnap,
portupgrade, etc utilities, you would pull the current version ports and
NOT from teh directory of the 5.4 ports. I.E, risk breaking the
production box.  So you should not use portsnap ever except for dev
boxes.

I have always used portsnap to set up a new machine.  I have never had
it pull a wrong port that I knew of.  I think it has to pay attention to
the version of the ports it is pulling.  


which is right?  This is a major issue with our production servers.
Thanks