Ucs or scf

Thanks Vitaliy Savranskiy, I had read the SOL but i could not find a straightforward answer.

For UCS it contains:

• All BIG-IP-specific configuration files
• BIG-IP product licenses
• User accounts and password information
• Domain Name System (DNS) zone files and the ZoneRunner configuration
• Secure Socket Layer (SSL) certificates and keys

For SCF it contains:

• All native BIG-IP system configuration elements
  • bigip.conf
  • bigip_base.conf
  • bigip_user.conf
• BIG-IP module configuration
  • BIG-IP GTM, ASM, and APM.
• Essential Linux configuration elements
  • /etc/resolv.conf
  • /config/ssh/sshd_config
  • /config/ntp.conf
  • /etc/localtime
  • /etc/sysconfig/clock
  • /config/bigip/auth/pam.d/system-auth
  • /config/bigip/auth/pam.d/httpd
  • /config/httpd/conf/httpd.conf
  • /config/httpd/conf.d/ssl.conf
  • /var/run/config/httpd.conf.d/mod_auth_pam.conf
  • /etc/logrotate.conf
  • /etc/logrotate_common.conf
  • /etc/syslog-ng/syslog-ng.conf
  • /etc/hosts
  • /etc/sysconfig/network
  • /config/bigip/auth/userroles
  • /etc/hosts.allow
  • /config/snmp/snmpd.conf

I am still confuse on whether UCS or SCF is more optimal when using it to do migration.