FC up2date with development/

[P.I.Julius]

Hello All,

I know that a question similar to this has been asked on this list, but
i want to be sure that i understand it correctly.

If i install FC2-test1 on my box and i point my yum to the development
tree:

[development]
name=Fedora Core $releasever - Development Tree
baseurl=ftp://download.fedora.redhat.com/pub/fedora/linux/core/development/$basearch

and i upgrade all packages from the development tree it is enough to
have FC2-test2 installed or i should download the FC2-test2 to have the
all new packages? 

Or simply, it is enough if i update my release always from the
development tree to have the latest release/test release installed on my
box? or i should download the released isos every time and then upgrade
to the development tree to have the latest and newest packages?

Thanks a lot,
Julius