packages (binary) update best practice

[Roberto]

Hi all,
I have update recently to freebsd 9.1 via freebsd-update and I was quite
happy with the process and the instructions on freebsd-handbook, I think
well documented.

But I would like to understand what is the best practice to update the
ports too as I used the package tools (pkg_add -r) to add few package to
the base install. Keeping in mind my server have disk space constrain
(small disk install) I would ask an opinion about the followings methods to
upgrade packages after a freebsd upgrade (in this case from 9.0 to 9.1):

1) perform

# pkg_delete <pkg_name>
and then
# pkg_add -r <pkg_name>

for each of them ? (I think about some package depends on other, this could
create some little problem);

2) perform
# pkg_add -F <pkg_name>
(not tried yet) and overwrite the already installed pkg ?

3) have a separate server on which create an update pkg from ports (ie from
source) ?

4) use the new package system pkgng, converting the existing installation ?
(this operation is not reversible, so I am waiting before doing this)

I would have some ideas on this topic please, from a security perspective;

Thanks
Roberto