[CentOS] Update only of security vulnerabilities?

Hi All :)

What is the best way to get a list of available security updates?
I found several commands for that:
1) yum updateinfo list updates -q --security
2) yum list-security --security -q
3) yum --security check-update -q
Based on the sample output below I think I can use any of the three with
some awk to get a list of packages.

yum updateinfo list updates -q --security
FEDORA-EPEL-2014-0525 security libyaml-0.1.5-1.el6.x86_64
FEDORA-EPEL-2014-0990 security libyaml-0.1.6-1.el6.x86_64

yum list-security --security -q
FEDORA-EPEL-2014-0525 security libyaml-0.1.5-1.el6.x86_64
FEDORA-EPEL-2014-0990 security libyaml-0.1.6-1.el6.x86_64

yum --security check-update -q
libyaml.x86_64                       0.1.3-4.el6_6
updates

Then I can add this to nagios or cron to get a notification about available
security updates.

Do you see any advantages/disadvantages in using one of the three choices?

How do you do this kind of task? What can you propose to get a notification
about available security updates?

BR,
Rafal.