/usr/src/UPGRADING procedure info

[Justin C. Sherrill]

/usr/src/UPGRADING says:
"The best way to upgrade DragonFly is to maintain a copy of the DragonFly
CVS repository via cvsup and to checkout the source base and DragonFly
ports via this repository."

If a person shortcuts this and just pulls a "checked out" copy (*default
release=cvs tag=.), what does that change?  (Other than not using an extra
500M.)  

I ask this because I am thinking that the most common path for most users is
going to be pulling the checked out copy, but this is only mentioned in the
DragonFly cvsup file.  If that's the case, then it should be the process
described first.