Do I need to upgrade CLDX 10.2 to 10.4 using .iso?

Some months ago I installed CLDX 10.2. Now I keep an actual state of CLDX system using “eix-sync”, “emerge -uD system” and “emerge -uD world”. Should I follow http://www.calculate-linux.org/main/en/system_update_guide and downdload iso file with version 10.4 to upgrade? Is there any advantages of upgrading the system using iso file and calculate utility?

If you are upgrading packages from portage and overlay of the Calculate, you stayed cldx-meta, the difference will not be.