How secure is the openSUSE Build Service?

With the releae of openSUSE 10.3, openSUSE introduced 
 '1-Click Install' . However openSUSE only has security support for it's
oss and non-oss repositories. 

How great of a security risk is adding third-party repositories which
you can hardly verify ( http://download.opensuse.org/repositories/ )?
What are the risks of getting rootkits and/or security exploits.  

Is openSUSE's approach more risky then Gentoo/FreeBSD which provides
security fixes for all packages in their tree?



-- 
Regards,

Aniruddha