Updating my CLX install with cl-install

As I have been using portage for Updating
eix-sync
emerge -uDN world

Now I am trying to correctly perform an Update by an Image iso
So, I downloaded the March 7 stage iso for my CLX install.
IF I perform from my desktop
…become root user to Update the CLX on my /dev/sda2

su
cl-install -U -d /dev/sda2

Would that correctly Update my install while perserving my configs, package parameters and Users.
OR
Once performed would I have to do manual reconfiguring of my Desktop and Packages which I had Already installed and configured previously.

thank You

This update perfoms to second root partition. This moves users and their settings, and network settings into the new system. Self-installed applications, as well as a customized system settings are not migrated to the new system.

Thank You
No, it seems that is not my goal.
My CLX is already at /dev/sda2
and in addition I have self installed many many development tools and customized them as well as the Desktop environment.

By your description I would simply have a New or almost New updated install.
My best option is to learn to properly Update with portage as in

eix-sync
emerge -uDN world